Beat the butter at room temperature with the eggs. Add condensed milk and whisk.
Sift the flour, quench the soda with vinegar and add to the dough, mix thoroughly.
Divide the ready dough into 2 parts, add cocoa into one part, mix.
Heat the oven to 180 degrees. Forms lubricate with butter, bake 2 cakes until tender (about 20 minutes).
Prepare a cream for the cake: lightly whisk the sour cream with sugar.
Cut the finished cakes into 2 parts and cut the sides. Pierce all the cakes of sour cream except the bottom one with a fork in order to better absorb the cream.
Smear all the cakes with cream and place in the form of a cake. Spread the cream and sides of the cake.
Cut the crumbs into crumb, and sprinkle them on sour cream. Cake put in the refrigerator soak overnight.
I tried this recipe and while it was tasty, I found it a bit too salty.