Karpatka

Ingredients:
1/2 cup of butter
1 cup of water
1 cup of flour
5 eggs
1 teaspoon of baking powder

Cream:
1 cup of butter
4 cups of milk
1 cup of sugar
5 tablespoons of white flour
5 tablespoons of potato starch
5 egg yolks
1 pack of vanilla sugar

For decorating:
icing sugar

Procedure:
Mix the flour, baking powder and salt together. 
In a medium saucepan, bring water, butter and salt to boil.
When the butter has completely melted, remove from heat and add flour mixture. 
Return to stove and mix over low heat for 2 or 3 minutes.
Remove from heat and beat in eggs one at a time. Batter should be smooth and glossy.

Pour dough into prepared pans and smooth it out. 
Bake 25 minutes or until top is golden brown and dry. 
Remove from pan and let cool completely on a wire rack before filling.

Cream:
In a mixing bowl, mix one cup milk, flour, potato starch, egg yolks and vanilla. Mix until well combined.
In a medium saucepan, bring milk to boil and add sugar, stirring until dissolved.
Reduce heat add egg mixture and continue to cook and mix for 2 minutes. Stir in vanilla sugar.
Let it cool to room temperature, covered with plastic wrap not to form the crust. 
Make sure the filling is completely cool before beating in softened butter.
Remove one cake from the pan and line it with a parchment paper. 
Place it half back in the pan and pour the filling over, spreading evenly. 
Top with the other half of dough and refrigerate for at least 1 hour. 
When ready to serve, dust heavily with icing sugar to look like snow on a mountain.

Thanks to Kinga Fryzowicz for this recipe.