Preheat the oven to 350°F (175°C). Line three 9-inch round cake pans with parchment paper and spray with nonstick cooking spray for easy removal.
In a large bowl, mix together the granulated sugar, light brown sugar, all-purpose flour, sifted cocoa powder, baking soda, baking powder, and salt until well combined.
In another bowl, combine the eggs, egg yolks, sour cream, milk, vegetable oil (or melted coconut oil), and vanilla extract. Pour this wet mixture into the dry ingredients and mix until just combined. Be careful not to overmix!
Add the hot water to the batter and mix until smooth. The batter will be thin, but this ensures a moist cake.
Divide the batter evenly among the prepared pans. Bake for 30 minutes or until a toothpick inserted into the center comes out clean. Keep an eye on the cakes in the oven to avoid overbaking.
Once baked, cool the cakes in the pans for 10 minutes, then transfer them to a cooling rack to cool completely.
For the frosting, cream the very soft unsalted butter in a stand mixer on medium speed until light and fluffy. Gradually add the sifted confectioners’ sugar, sifted cocoa powder, vanilla extract, salt, heavy cream, and salted caramel sauce. Beat until smooth and creamy, adjusting the consistency with more heavy cream if necessary.
Once the cakes are completely cooled, trim the tops to make them level. Place one layer on a serving plate, spread a layer of frosting, and drizzle with some salted caramel sauce. Repeat with the other layers.
Chill the assembled cake in the refrigerator for about 1 hour to set the frosting.
Finish frosting the top and sides of the cake with the remaining frosting. Drizzle with additional salted caramel sauce and sprinkle with flaky sea salt for an impressive finish.
Slice, serve, and enjoy your decadent chocolate cake! Store any leftovers in the refrigerator for up to 5 days.
Notes
For a richer flavor, you can add a touch of coffee to the chocolate cake batter. No alcoholic drinks allowed, please substitute with a non-alcoholic option.
Keyword Decadent Chocolate Cake with Salted Caramel Frosting Recipe