Cake

1. Preheat the oven to 350 degrees F. Prepare two 9-inch baking pans by lining them with parchment and spraying with cooking spray. (I like to spray the pan first, then put the parchment down, then spray the parchment again.)
2. In a small bowl, whisk together flour, sugar, baking powder and salt. In the bowl of a stand mixer, beat butter, sour cream, eggs and vanilla until smooth – slowly add the flour mixture and beat at medium speed until smooth and satiny, scraping the sides of the bowl as necessary. (about 30 seconds.)
3. Divide the batter between the two pans and bake until a cake-tester comes out clean, about 28 minutes. Let sit in the pan for 5 minutes, then remove and allow to cool completely on a cooling rack.

Coffee Syrup

1. In a small saucepan over low heat, whisk together coffee and sugar until the sugar is dissolved. Remove from heat and allow to cool. Once cool, stir in liqueur.

Filling

1. Combine ingredients in a small bowl using a hand mixer. Beat until light and fluffy.

Frosting

1. In the bowl of a stand mixer fitted with the whisk attachment, whip the cream until stiff. Add sugar and liqueur and whisk until just combined.

To Assemble

1. Using a large serrated knife, level or flatten the tops of the cake layers if necessary. Eat the leftover cake scraps. Using a pastry brush, liberally brush the tops of both cakes with the coffee syrup mixture.
2. Place the bottom layer of the cake on a cake board or your serving plate. Top with half of the filling mixture.
3. Soak the lady fingers in the remaining coffee syrup mixture. Arrange the soaked lady fingers on the first layer of cake. Do not allow the edges of the ladyfingers to expand outside the edge of the cake. You can cut/break the ladyfingers if necessary to make them fit better.
4. Top the ladyfingers with the remaining filling. Use a soft spatula to push some of the filling down between the ladyfingers as much as possible.
5. Place the top layer of cake on top of the filling.
6. Frost the top and sides of the cake with the frosting. Sprinkle with cocoa powder
7. Refrigerate the cake for30-60 minutes before serving, and store (covered) in the refrigerator for up to 3 days.