1-First, sift together the flour and cocoa powder then set it aside, as this helps with even mixing. Next, beat the egg and sugar with a whisk attachment on medium speed for about 6 minutes until it’s light and airy. Add the softened butter, warm milk, and baking soda; mix on medium/high speed for 3 minutes until smooth.

2-Place the mixture in a heat-safe bowl over boiling water steam, stirring for 10 minutes to thicken it up. Remove from heat and immediately stir in the sifted flour and cocoa mixture; let the dough stand for 20 minutes until it’s warm and thickened. Preheat your oven to 350°F and get ready to shape your layers.

3-Shaping and Baking the Layers: Place a heaping tablespoon of dough on large parchment paper and sprinkle flour over it to prevent sticking. Roll it out to a thin 9-inch circle and cut it with a pizza cutter using a plate as a guide; save the scraps in a bowl. Bake the layers on parchment on the middle oven rack for 4-5 minutes until the edges just brown, then cool them completely.

4-For the cream, beat the softened butter and sweetened condensed milk on medium speed for 7 minutes, scraping the bowl as needed. Gradually add the cream cheese until smooth, about 2-3 minutes. In another bowl, beat the cold heavy whipping cream and powdered sugar until stiff peaks form, then fold it into the butter mixture.

5-Assembling and Finishing: To assemble, place a cake layer on parchment and spread the frosting evenly; repeat with the remaining layers, pressing gently. Frost the sides, crush the reserved baked scraps, and sprinkle them over the top and sides. Refrigerate overnight for about 10 hours to let the layers soften. This step ensures your Chocolate Spartak cake with creamy frosting reaches its full potential.