Preheat the oven to 325°F (163°C). Spray two 8-inch round cake pans with pan spray, line the bottoms with parchment rounds, and spray the parchment. Set the pans aside.

In a large bowl, whisk together ¾ cup vegetable oil, 1 ¼ cup warm coffee, 2 large eggs (room temperature), and 2 ¼ teaspoons vanilla extract until combined.

In a separate medium bowl, sift (or whisk) together 2 cups all-purpose flour, 1 ½ cup granulated sugar, ¾ cup unsweetened cocoa powder (not Dutch process), 2 teaspoons baking soda, and 1 teaspoon salt.

Add the dry ingredients to the wet ingredients and gently whisk until just combined and no large pockets of dry flour remain. Do not overmix.

Divide the batter evenly between the two prepared pans and smooth the tops. Bake for 30–35 minutes, or until the centers spring back lightly when pressed and a toothpick inserted in the center comes out clean or with a few moist crumbs.

Let the cakes cool in their pans on a wire rack for 10 minutes. Run a knife around the edges, invert each pan onto the rack, and remove the parchment rounds. Let the cakes finish cooling completely on the rack.

Once the cakes are completely cool, wrap each cake layer tightly in two layers of plastic wrap and refrigerate for at least 4 hours (this firms them and makes them easier to trim and assemble).

Prepare the white chocolate ganache: place 6 ounces chopped white chocolate in a heatproof bowl. In a small microwave-safe container, heat ⅓ cup heavy whipping cream and 1 tablespoon butter together until steaming (about 45 seconds, depending on your microwave). Pour the hot cream and butter over the white chocolate, let sit 1 minute, then stir until smooth and fully melted. Cover and let the ganache sit at room temperature until it firms up slightly (about 30 minutes).

When the white ganache has cooled and begun to set, use a hand mixer to whip it until light and fluffy. Set the whipped white chocolate ganache aside at room temperature.

Prepare the dark (semi-sweet) chocolate ganache: place 16 ounces chopped semi-sweet chocolate in a heatproof bowl. Heat 2 cups heavy whipping cream until steaming (about 90 seconds in the microwave). Pour the hot cream over the chocolate, let sit 2 minutes, then whisk until smooth and fully combined.

Let the dark ganache cool to room temperature, or speed cooling by placing it briefly in the refrigerator for about 20 minutes. Once cooled, whip the ganache with a stand mixer or hand mixer fitted with the whisk attachment on high for 3–4 minutes, until the ganache lightens in color and becomes very fluffy.

If either cake layer has a dome, level the tops with a serrated knife so both layers are flat.

Place one cake layer on your cake stand or serving plate. Spread a very thin thin layer of the whipped dark ganache over the top (this is a thin base layer). Fit a piping bag with a large round tip (or use a squeeze tool) and pipe a thick ring of whipped dark ganache around the outer edge of the cake top to form a dam.

Spoon the whipped white chocolate ganache into the center of the dam and gently spread it to meet the dark ganache ring, keeping the white ganache level and contained by the dam. Place the second cake layer on top, pressing very gently to level.

Use an offset spatula to spread the remaining whipped dark ganache over the top and around the sides of the cake, smoothing as you go. If the ganache becomes too soft while you work, chill the cake briefly to firm it, then continue smoothing.

Chill the assembled cake briefly to set the ganache before serving. Store any leftovers covered in the refrigerator.