Preheat oven to 350°F. Grease a 9X13 inch baking dish. In a large bowl beat butter flavored palm shortening, sugar, baking powder, and salt with an electric mixer until well combined, scrapping the sides of the bowl occassionally. Beat in eggs and vanilla until smooth. Using the mixer beat in 2 cups of the Nu Life Market Gluten Free All-Purpose Flour. With a spatula, mix in the remaining 1 cup of the All-Purpose Flour until well combined. In a small bowl reserve 1½ cups of the batter and set aside for later use. Press the remaining batter into the greased 9X13 baking dish and bake for 12 minutes. Remove from the oven and spread the pie filling over the crust. Spoon the reserved batter over the top of the pie filling, making small mounds, and bake for 25-30 minutes or until the top is golden brown. Allow to cool. In a small bowl combine powdered sugar, vanilla, and dairy free milk. Drizzle over cooled bars, cut and serve.