Bittersweet Chocolate Cake with Salted Butterscotch Buttercream

1. Prepare Cake Pans and Preheat Oven

Begin by preheating your oven to 350°F (180°C). While the oven warms, generously grease three 8-inch cake pans with unsalted butter, and line the bottoms with parchment paper. This will help your cake layers to release effortlessly once baked.

2. Mix Dry Ingredients

In a large bowl, whisk together the dry ingredients: all-purpose flour, dark brown sugar, sifted cocoa powder, baking soda, and sea salt. Whisking these dry components thoroughly ensures your cake will have a consistent texture and flavor throughout.

3. Combine Wet Ingredients with Dry

To the bowl of dry ingredients, add neutral oil, white distilled vinegar, vanilla extract, and warm brewed coffee. Whisk everything together until you have a smooth batter. The coffee not only adds moisture but also intensifies the chocolate flavor without overpowering it.

4. Bake the Cake

Divide the batter evenly among the prepared cake pans, aiming for about 1 pound (450 g) of batter per pan. This even division helps the layers bake uniformly. Place the pans in your preheated oven and bake for 20 to 25 minutes. You'll know they are done when the tops spring back gently when pressed.

5. Cool the Cake

Once baked, let the cake layers cool in their pans for 5 minutes. Then, carefully transfer them to wire racks to cool completely. This step is crucial for maintaining the cake’s structure as it cools.

6. Assemble the Cake

If you're assembling a layer cake, gather your piping bag, buttercream, and salted butterscotch sauce. Pipe a layer of buttercream onto the first cake layer, then drizzle with about ⅓ cup (80 ml) of salted butterscotch sauce. Repeat this for each layer.

7. Finish and Serve

Stack the cake layers carefully, ensuring they are aligned. Use the remaining buttercream to frost the cake, creating a 'naked edge' effect if you prefer a more rustic look. Just before serving, drizzle the top with the remaining butterscotch sauce. For an extra touch, serve slices with a scoop of vanilla ice cream.