Preheat your oven to 350°F (175°C). Grease three 9-inch round cake pans and line the bottoms with parchment paper for easy removal.
In a medium saucepan over low heat, melt the butter and ¾ cup of Dutch-process cocoa powder together until smooth. Stir in the hot water and remove from heat. Allow the mixture to cool slightly.
In a large mixing bowl, whisk together the all-purpose flour, espresso powder, baking soda, and salt. Set aside.
In another bowl, whisk together the granulated sugar, buttermilk, eggs, and vanilla extract until well combined. Gradually add the cooled chocolate mixture to the wet ingredients and mix until smooth.
Gradually add the dry ingredient mixture to the wet mixture, stirring until just combined. Do not overmix; a few lumps are fine!
Divide the batter evenly among the prepared cake pans. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove the cakes from the oven and let them cool in the pans for about 10 minutes. Then, turn them out onto a cooling rack to cool completely.
In a large mixing bowl, beat together the room temperature unsalted butter, vegetable shortening, and sifted powdered sugar until creamy. Add the sifted cocoa powder, semisweet chocolate chips, vanilla extract, and heavy cream. Beat until the frosting is light and fluffy. Adjust the consistency with more cream or powdered sugar if needed.
Once the cakes are completely cool, place one layer on a serving plate. Spread a generous amount of frosting on top. Add the second layer and repeat. Top with the final layer and frost the top and sides of the cake.
For an extra touch, you can decorate the top with chocolate shavings, chocolate chips, or even fresh berries. Slice, serve, and enjoy your Homemade Choco-Bliss Snack Cakes!
