Preheat oven to 375 degrees F (190 degrees C). In a medium bowl, mix together the butter and shortening. In a separate bowl, combine the flour, baking powder and salt. Gradually add the dry ingredients to the butter mixture, mixing until crumbly. Gradually add in the cold water until a dough forms. Roll out dough on a lightly floured surface until it is about 1/8 inch thick. Cut out circles using a biscuit cutter or the rim of a glass.
Place about 2 tablespoons of filling onto each circle. Fold dough in half over the filling and press edges together to seal. Place onto an ungreased cookie sheet and bake for 25 minutes or until golden brown.