If using my Flaky Pie Crust for this recipe, go there and mix up and roll out ingredients or... In a large bowl, combine flour, baking powder, and salt. Cut in butter until crumbly. Gradually add water until dough sticks together.
Turn onto floured surface and knead 10-12 times until smooth. Set aside 1/3 of the dough. Press remaining dough into two 9×13? casserole dishes.
Mix together filling ingredients in a large bowl and spread half over each crust.
Roll out remaining dough on a well-floured surface and cut into strips. Lay strips over filling to form lattice-work.
Bake at 400° for 50 minutes. Let cool slightly before serving.