Preheat oven to 350 degrees. In a large bowl beat butter and shortening with an electric mixer on medium speed for 30 seconds. Add sugar, baking powder and salt. Beat until combined, scraping side of bowl occasionally. Beat in eggs and vanilla until combined. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour. Reserve 1 ½ cups of the dough. Press the remaining dough on to the bottom of an ungreased 15x10x1-inch baking pan.

Bake for 12 minutes. Remove, then spread pie filling over crust in pan. Spoon reserved dough into small mounds over pie filling.

Bake an additional 30 minutes or until top is light brown. Cool in pan on a wire rack for 10 minutes. Drizzle with powdered sugar icing. Cut and serve.