Pour 1/2 tsp of soda into a glass, pour 1/2 cup of hot water into it. Mix in the form of flour, condensed milk, eggs and melted butter. All ingredients mix well.
Divide the dough into two parts, add cocoa to the second part.
Bake cakes in the oven until tender, at a temperature of 190 degrees for 20-25 minutes. Hotcakes cut in half.
Beat sour cream and sugar, soak cream cakes.
Sprinkle with grated chocolate on top.
Let it stand at room temperature so that the cake is soaked. Optionally, you can remove it for several hours in the refrigerator.