Ingredients
Method
Prepare the Cake
- Preheat the oven to 350°F. Line the bottoms of three 8-inch round cake pans with parchment paper, grease the sides, and dust with cocoa powder.
- In a large bowl, sift together the flour, cocoa powder, baking soda, baking powder, and salt. Whisk in the granulated sugar.
- Make a well in the center. Add the coffee mixture, buttermilk, oil, eggs, and vanilla extract. Beat with an electric mixer on medium speed for 90 seconds until smooth.
- Divide the batter evenly among the prepared pans (use a kitchen scale for accuracy). Bake for 27 to 30 minutes, rotating pans halfway through, until a toothpick inserted in the center comes out with a few moist crumbs.
- Remove from the oven and gently press down on the domed tops with the bottom of another pan to flatten slightly. Let cool in the pans for 10 minutes, then turn out onto a wire rack to cool completely.
Make the Buttercream
- In a stand mixer fitted with the paddle attachment, beat the softened butter, powdered sugar, and 2/3 cup of caramel sauce on low speed until combined, then increase to high and beat for 4 to 5 minutes until light and fluffy. Scrape down the sides as needed.
- Taste and add a pinch of salt if you want a stronger salted caramel flavor.
- Transfer all but about 3/4 cup of the buttercream to a piping bag fitted with a large star tip.
Assemble the Cake
- Place one cake layer on a serving plate, domed side up. Pipe a ring of stars around the edge, then spread half of the reserved plain buttercream in the center. Drizzle about 2 1/2 tablespoons of the extra caramel sauce over the buttercream.
- Top with a second cake layer, domed side down. Repeat the piping, spreading, and drizzling steps.
- Place the third cake layer on top, flat side up. Pipe stars of buttercream all over the top, or spread the remaining buttercream in swirls. Drizzle the remaining caramel sauce over the top, letting it drip down the sides.
- Serve immediately or refrigerate until ready. Remove from the fridge at least 1 hour before serving for best texture.
Nutrition
Notes
For the best flavor, make the caramel sauce from scratch 1 to 3 days ahead; it should be thick and salty. If your caramel is too thin, chill it before using. To cut the recipe to 2 layers, use 2 cups flour, 3/4 cup cocoa, 2 tsp baking soda, 1 tsp baking powder, 1/2 tsp salt, 1 1/4 cups sugar, 1 cup buttermilk, 1/2 cup oil, 2 eggs, 1 tsp vanilla, and 1 tbsp instant coffee in 1 cup hot water; for the frosting, use 8 oz butter, 1/2 cup caramel sauce, 2 cups powdered sugar, and 1/3 cup extra caramel. Store leftovers in an airtight container in the fridge for up to 5 days. Let the cake come to room temperature before serving for the softest crumb. If you don't have buttermilk, add 1 tbsp lemon juice to 1 1/2 cups milk and let sit 5 minutes. For even layers, weigh the batter or use a measuring cup.