Plăcinta de fructe

Ingredients:
For the filling
5 cups mixed berries
1 cup water
4 tbsp corn starch
3/4 cup sugar
1 tsp vanilla

For the crust:
2 eggs
100g butter
1 tbsp baking powder
1/2 tsp dry yeast
1 cup milk
1/4 cup sugar
3-4 cups flour
Pinch of salt