Four Layer Cake with strawberries,raspberries and Tvorog cream filling

This is a delicate cake filled with red berries ,Russian tvorog cream, and Finished with whipped cream. Russian tvorog is something like curd cheese ,cottage cheese,or ricotta cheese. All of them have something in common but yet its different. There is alot of recipes online on how to make it yourself.
You will need to bake two cakes then cut it half.
Ingredients for 1 cake(you will need 2):
4 eggs
4 tablespoons sugar
2 tablespoons flour
2 tablespoons potato starch
1 teaspoons baking powder
9'' baking pan

Preheat oven to 350 degrees.
Beat together eggs with sugar until light and fluffy.In a separate bowl mix together flour,starch and baking powder. Gradually add the flour mix to the egg mixture , and mix carefully with a spatula or wooden spoon. Grease the baking pan and transfer the batter in to the pan. Bake for about 20 minutes.

Cream:
1 can condensed milk
1 ½ cup Tvorog
1 stick butter (room temp.)
2 tablespoons sour cream
1 pint heavy whipping cream
1 cup powdered sugar
Strawberries sliced
Raspberries
*You can add some powdered sugar if the cream is not sweet enough.

Directions:

Whip together heavy whipping cream and powdered sugar.
In separate bowl beat butter in till slightly light and creamy. Add condensed milk, tvorog and sour cream. Mix it well.Carefully fold in four tablespoons of whipped cream.

Slice the cakes in half.On the first layer spread some tvorog cream. In single layer add strawberries and raspberries.Place next layer of cake on top of creamed cake,and repeat the steps for the rest of the layers as in the first layer. Cream the outside of the cake with remaining whipped cream. Decorate the cake as you wish.
* This cake is better if served the same day.