This moist chocolate caramel cake has three tender chocolate layers made in one bowl, filled with salted caramel sauce and frosted with a whipped chocolate caramel buttercream.
Prep: Preheat your oven to 180°C (350°F). Grease three 8-inch cake pans and line the bottoms with parchment paper.
Dry Ingredients: In a large mixing bowl, add the flour, sift in the cocoa powder, then add the baking powder, baking soda, salt, and sugar. Whisk to combine.
Wet Ingredients: Add the eggs, buttermilk, oil, and vanilla extract and mix until almost combined.
Add the Coffee: Pour in the hot coffee and mix until the batter is smooth with no lumps of flour. The batter will be thin.
Bake: Divide the batter evenly between the pans, weighing them for even layers. Bake for 25 to 30 minutes, until a toothpick comes out clean. Let the layers cool completely.
Make the chocolate caramel frosting
Mix: In a medium mixing bowl, add the powdered sugar and softened butter, sift in the cocoa powder, then add the heavy cream, vanilla extract, and salt. Mix on low until combined.
Whip: Add the cold caramel sauce and beat on high until the frosting is fluffy and smooth.
Assemble the cake
Anchor: Spread a small dab of frosting on your cake board or plate and place the first cake layer on top.
Dam and Fill: Pipe a ring of frosting around the edge of the layer, spread a thin layer of frosting inside it, then fill the center with about ⅓ cup of caramel sauce.
Stack and Frost: Top with the second layer and repeat. Add the third layer and cover the whole cake with the remaining frosting.
Notes
Caramel Sauce: Use my homemade salted caramel sauce or a thick store-bought caramel. You need about 1 cup in total: 2 tablespoons for the frosting and about ⅓ cup for each filling layer.
Caramel Temperature: Use cold caramel in the frosting so it doesn't thin the buttercream, and room temperature caramel for the filling so it spreads easily.
Eggs: Use large eggs at room temperature for an even, smooth batter.
Measure Accurately: Spoon and level the flour or weigh it, and divide the batter by weight so all three layers bake evenly.
Cool Completely: Frost only fully cooled layers, or the frosting will melt and the caramel will slide.
Chill Before Slicing: Refrigerate the finished cake for 30 minutes so the caramel and frosting set and the slices stay neat.
Other Pans: Bake in two 9-inch pans for 30 to 35 minutes, or a 9x13-inch pan for 35 to 40 minutes.
Storage: Keep covered in the fridge for up to 4 days. Let slices sit at room temperature for 20 to 30 minutes before serving.