Preheat your oven to 350°F (175°C). This ensures that your cake bakes evenly and rises beautifully.
Grease the two 9-inch round cake pans with butter or cooking spray. Dust them lightly with flour to prevent sticking.
In a large mixing bowl, combine the granulated sugar, light brown sugar, sour cream, canola oil, eggs, and vanilla extract. Using an electric mixer, beat the mixture on medium speed until it’s smooth and creamy.
In a separate bowl, sift together the all-purpose flour, cocoa powder, baking powder, baking soda, and salt. This step is crucial for removing lumps and ensuring a light texture.
Gradually add the dry mixture to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix; a few lumps are okay!
In a small bowl, dissolve the instant coffee granules in the hot water. Slowly pour this mixture into your batter, mixing gently until everything is well incorporated. The batter will be thin, but that’s what makes it so moist!
Divide the batter evenly between the prepared cake pans. Bake in the preheated oven for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Once baked, remove the cakes from the oven and let them cool in the pans for about 10 minutes. Then, transfer them to a cooling rack to cool completely.
While the cakes cool, prepare the frosting. In a large mixing bowl, beat the unsalted butter until creamy. Gradually add the sifted powdered sugar and cocoa powder, alternating with the heavy cream. Beat until the frosting is smooth and fluffy. Stir in the vanilla extract.
Once the cakes are completely cool, place one layer on a serving plate. Spread a generous amount of frosting on top, then place the second layer on top of the first. Frost the top and sides of the cake with the remaining frosting, smoothing it out with an offset spatula.
