Easy Single Layer Chocolate Cake
Quietly reliable and syrup-dark, this single-layer chocolate cake is the one I reach for when I want great chocolate with minimal fuss. It bakes in a single 9″ pan, needs no special equipment, and the batter comes together in one bowl plus one smaller bowl — which means more time to breathe and less to clean up.
The crumb is tender from sour cream and oil, and the cocoa-forward flavor is deepened by a splash of hot coffee. A simple whipped ganache finishes it: glossy, not too sweet, and whipped just enough to spread. I’ll walk you through the exact ingredients and the small decisions that make a big difference.
If you want an everyday cake that performs for birthdays, casual dinners, or tea-time rescue missions, this is it. Below you’ll find the ingredient list, the step-by-step method (unchanged), thoughtful swaps, common mistakes, and storage notes so you can bake with confidence.
The Ingredient Lineup
Ingredients
- 1 and 1/4 cups (150 grams) all-purpose flour — provides the cake’s structure; spoon into the cup and level for accuracy.
- 1/2 cup (43 grams) unsweetened cocoa powder — for chocolate intensity; use Dutch-process or natural, but note flavor varies.
- 3/4 cup (149 grams) granulated sugar — balances the cocoa and helps with tenderness.
- 1/2 cup (106 grams) light brown sugar, packed — adds moisture and a hint of caramel.
- 1/4 teaspoon baking soda — gentle lift and interacts with brown sugar for texture.
- 1/4 teaspoon baking powder — ensures even rise with the single-layer format.
- 1/2 teaspoon salt — sharpens the chocolate and balances sweetness.
- 2 large eggs, at room temperature — bind the batter and add richness; bring to room temp for best rise.
- 1/2 cup (99 grams) vegetable oil — keeps the crumb tender and stays moist over time (better than butter for make-ahead cakes).
- 3/4 cup (170 grams) sour cream — adds tang, tenderness, and moisture.
- 1/4 cup (57 grams) milk — thins the batter to the right consistency.
- 2 teaspoons vanilla extract — rounds the chocolate flavor.
- 1/3 cup (74 grams) freshly brewed coffee or freshly boiled water — amplifies the chocolate; freshly brewed coffee gives the best depth.
- 1 cup (170 grams) high-quality semi-sweet chocolate, finely chopped — for the ganache; higher-quality chocolate = better gloss and flavor.
- 1 teaspoon espresso powder (optional) — brightens the ganache’s chocolate notes if you choose to use it.
- 1/2 cup (113 grams) heavy cream — warmed to make the ganache smooth and shiny.
- Shaved chocolate, for decoration (optional) — adds texture and visual polish.
- Fresh raspberries, for decoration (optional) — bright, tart contrast to the rich ganache.
Step-by-Step: Single Layer Chocolate Cake
- Preheat the oven to 350°F (175°C). Spray a 9″ cake pan with non-stick baking spray and set aside.
- In a large bowl, whisk together 1 1/4 cups (150 g) all-purpose flour, 1/2 cup (43 g) unsweetened cocoa powder, 3/4 cup (149 g) granulated sugar, 1/2 cup (106 g) light brown sugar (packed), 1/4 teaspoon baking soda, 1/4 teaspoon baking powder, and 1/2 teaspoon salt until evenly combined.
- In a separate bowl, whisk together 2 large eggs (at room temperature), 1/2 cup (99 g) vegetable oil, 3/4 cup (170 g) sour cream, 1/4 cup (57 g) milk, and 2 teaspoons vanilla extract until smooth.
- Add the wet mixture to the dry mixture in three additions, folding gently with a rubber spatula each time just until incorporated. Do not overmix.
- Stir in 1/3 cup (74 g) freshly brewed coffee or freshly boiled water until the batter is evenly combined; it will be thin, dark, and velvety.
- Pour the batter into the prepared pan, smooth the top, and bake in the preheated oven for 45–50 minutes, or until a toothpick inserted into the center comes out clean.
- Remove the pan from the oven and place it on a cooling rack. Cool in the pan for 30 minutes.
- After 30 minutes, run a knife around the pan if needed, remove the cake from the pan, and cool completely on the rack before frosting.
- To make the ganache, place 1 cup (170 g) finely chopped semi-sweet chocolate and 1 teaspoon espresso powder (optional) in a medium heatproof bowl.
- In a small saucepan over medium heat, warm 1/2 cup (113 g) heavy cream just until it comes to a simmer (steam and small bubbles at the edge); do not let it boil. Remove from heat.
- Pour the hot cream over the chopped chocolate and let sit undisturbed for 2 minutes. Stir until the mixture is smooth and glossy.
- Chill the ganache in the refrigerator for 30 minutes. Then whisk gently until it becomes slightly fluffy and spreadable.
- Spread the whipped ganache over the completely cooled cake. Top with shaved chocolate and fresh raspberries, if using. Serve.
Why It Deserves a Spot
This cake is practical luxury. It’s not a fuss-free box cake; it’s carefully balanced so a single layer can still feel celebratory. The oil and sour cream keep it forgiving: it stays moist a day or two longer than a butter-based layer cake. Coffee quietly boosts the cocoa without adding a coffee flavor unless you stare for it.
It’s also a workhorse recipe. One pan, one middling oven time, and a simple ganache turn it into something you’d happily bring to a potluck, send with a friend, or put on a small party table. If you need a pretty cake fast, this is the one I use.
Swap Guide
Substitutions that work and the ones I avoid:
- Flour: You can replace all-purpose with a 1:1 gluten-free blend, but expect a slightly crumblier texture.
- Cocoa powder: Natural or Dutch-process both work, but flavor and color will shift; if you use Dutch-process, the cake will be darker and milder.
- Vegetable oil: Neutral oils like canola or light olive oil are fine. I don’t recommend melted butter unless you adjust other liquids — butter can firm up the crumb.
- Sour cream: Greek yogurt (full-fat) works as a swap at a 1:1 ratio for tang and moisture.
- Coffee: Freshly brewed is best; if you can’t have coffee, use freshly boiled water. Don’t skip the hot liquid — it blooms the cocoa.
- Chocolate for ganache: You can use milk chocolate for a sweeter, milder ganache or bittersweet for more intensity. Adjust the optional espresso powder to taste or omit.
Toolbox for This Recipe
Must-haves
- 9″ cake pan — a standard round pan for even baking.
- Mixing bowls — one large for dry ingredients and one for wet.
- Rubber spatula — for folding without overworking the batter.
- Whisk — for dry mixing and the wet mixture.
- Small saucepan and heatproof bowl — for making the ganache.
- Cooling rack — essential to cool the cake fully before frosting.
Nice-to-have
- Offset spatula — for smooth ganache spread.
- Instant-read thermometer — not necessary, but a toothpick that comes out clean at 45–50 minutes is your cue.
- Microplane — if you plan to shave chocolate for decoration.
Slip-Ups to Skip
Three common mistakes I see:
- Overmixing: Fold the wet into dry in three additions, and stop when it’s just combined. Overworking the batter produces a dense crumb.
- Baking too hot or too long: Every oven runs a bit differently. Start checking at 45 minutes; pull when a toothpick comes out clean. If the top browns too fast, tent with foil.
- Frosting a warm cake: Ganache will melt and run. Cool completely on a rack before spreading.
Fit It to Your Goals
Want to adapt this cake to dietary or timing goals? Here’s how:
- Lower sugar: This recipe relies on sugar for structure and moisture. You can reduce granulated sugar slightly, but expect a denser cake and a less glossy ganache.
- Make-ahead: Bake the cake a day ahead, wrap it tightly once cooled, and keep it at room temperature. Make the ganache the day you plan to serve and spread it just before.
- Party-ready: Double the ganache and pipe rosettes, or slice the baked cake into layers horizontally for a two-layer look — the batter is forgiving but keep the bake time the same per layer.
What I Learned Testing
Hands-on, a few small practices made the biggest difference. Room-temperature eggs improved rise and crumb. Folding the wet ingredients in three additions avoids streaks without overmixing. The batter is meant to be thin; resist the urge to add more flour if it looks runny — that’s normal.
For the ganache, timing is everything. Let the cream sit over the chopped chocolate for the full two minutes before stirring; that rest yields a silky emulsion. Chill the ganache until slightly fluffy — whip too long and you’ll end up with grainy texture.
Meal Prep & Storage Notes
Storage is simple.
- At room temperature: If the kitchen is cool and dry, keep the frosted cake covered for up to 2 days.
- Refrigerator: Store in an airtight container for up to 5 days. Bring to room temperature before serving so the ganache softens slightly.
- Freezing: You can freeze an unfrosted, fully cooled cake wrapped tightly for up to 2 months. Thaw in the refrigerator overnight and bring to room temp before frosting.
Single Layer Chocolate Cake Q&A
Q: Can I make this gluten-free?
A: Yes — use a 1:1 gluten-free flour blend that contains xanthan gum. Texture will be slightly different, but the oil and sour cream help keep moisture.
Q: The center sank; why?
A: Underbaking or opening the oven door too early are the usual suspects. Make sure the cake reaches a clean toothpick and avoid checking in the first 30 minutes.
Q: Can I skip the coffee?
A: You can use freshly boiled water, but coffee deepens the chocolate flavor. If you avoid caffeine, decaf brewed coffee works just as well.
Q: My ganache is grainy. Help.
A: Grainy ganache often comes from cooling too quickly or from chocolate that’s too cold when you add the hot cream. Chop the chocolate finely, pour hot cream over it, let it sit 2 minutes, then stir gently until smooth. If needed, warm gently over a double boiler while stirring to smooth it out.
In Closing
This Single Layer Chocolate Cake is the kind of recipe I keep at my fingertips: straightforward, forgiving, and reliably delicious. It balances convenience and quality — a single pan, pantry-friendly ingredients, and a small whipped ganache that reads celebratory without being fussy.
Bake it for a weeknight treat or a small celebration. Decorate with shaved chocolate and raspberries if you want it to look special, or leave it simple. Either way, the cake rewards careful mixing and a calm hand at the end. Happy baking — and let me know how yours turns out.
Easy Single Layer Chocolate Cake
Ingredients
Equipment
Method
- Preheat the oven to 350°F (175°C). Spray a 9" cake pan with non-stick baking spray and set aside.
- In a large bowl, whisk together 1 1/4 cups (150 g) all-purpose flour, 1/2 cup (43 g) unsweetened cocoa powder, 3/4 cup (149 g) granulated sugar, 1/2 cup (106 g) light brown sugar (packed), 1/4 teaspoon baking soda, 1/4 teaspoon baking powder, and 1/2 teaspoon salt until evenly combined.
- In a separate bowl, whisk together 2 large eggs (at room temperature), 1/2 cup (99 g) vegetable oil, 3/4 cup (170 g) sour cream, 1/4 cup (57 g) milk, and 2 teaspoons vanilla extract until smooth.
- Add the wet mixture to the dry mixture in three additions, folding gently with a rubber spatula each time just until incorporated. Do not overmix.
- Stir in 1/3 cup (74 g) freshly brewed coffee or freshly boiled water until the batter is evenly combined; it will be thin, dark, and velvety.
- Pour the batter into the prepared pan, smooth the top, and bake in the preheated oven for 45–50 minutes, or until a toothpick inserted into the center comes out clean.
- Remove the pan from the oven and place it on a cooling rack. Cool in the pan for 30 minutes.
- After 30 minutes, run a knife around the pan if needed, remove the cake from the pan, and cool completely on the rack before frosting.
- To make the ganache, place 1 cup (170 g) finely chopped semi-sweet chocolate and 1 teaspoon espresso powder (optional) in a medium heatproof bowl.
- In a small saucepan over medium heat, warm 1/2 cup (113 g) heavy cream just until it comes to a simmer (steam and small bubbles at the edge); do not let it boil. Remove from heat.
- Pour the hot cream over the chopped chocolate and let sit undisturbed for 2 minutes. Stir until the mixture is smooth and glossy.
- Chill the ganache in the refrigerator for 30 minutes. Then whisk gently until it becomes slightly fluffy and spreadable.
- Spread the whipped ganache over the completely cooled cake. Top with shaved chocolate and fresh raspberries, if using. Serve.
Notes
Full-Fat plain yogurt or Greek yogurt will work as a substitute for sour cream
Canola oil or melted coconut oil can be used instead of vegetable oil
This cake is best served the day it's made, but will keep, tightly wrapped in plastic wrap, for up to 3 days.
You can freeze this cake (unfrosted) for up to 1 month.
