01 -
If preparing homemade chocolate fudge frosting, make it ahead to allow it to set before using.
02 -
Preheat oven to 180°C. Line the bases of two 20-cm round cake pans with parchment paper and set aside.
03 -
In a stand mixer bowl, blend cake flour, granulated sugar, dark brown sugar, baking powder, baking soda, and salt. Add cubed unsalted butter and mix on low speed until mixture resembles coarse sand, approximately 3 minutes.
04 -
In a separate bowl with a spout, whisk together sour cream, whole milk, eggs, vegetable oil, and vanilla extract. In another bowl, whisk hot coffee with cocoa powder until smooth. Gradually add the first wet mixture to the dry ingredients, then immediately add the coffee-cocoa mixture. Mix until just combined, scraping down bowl sides as needed.
05 -
Divide the chocolate batter evenly between prepared cake pans, roughly 740 g per pan. Bake for 30–35 minutes or until a toothpick inserted in the center yields a few moist crumbs.
06 -
Place cake pans on a wire rack and cool for 20 minutes. Run an offset spatula around edges to loosen, invert layers onto the rack, and let cool completely before assembling.
07 -
In a small saucepan, combine water, unsweetened cocoa powder, granulated sugar, and vanilla extract. Cook over medium heat until boiling, reduce to low, and simmer for 2–3 minutes until thickened. Set aside to cool.
08 -
Carefully trim the tops of cooled cake layers. Use a pastry brush to apply chocolate soak evenly over the surface of each layer.
09 -
Layer cakes with chocolate fudge frosting and finish with additional frosting on top and sides. Optionally, garnish with chocolate shavings.