Preheat oven to 350. Prepare a 12" pizza pan with cooking spray and flour; set aside. To prepare crust, combine margarine, eggs, milk, and vanilla extract in a mixing bowl. In another mixing bowl, combine flour, granulated sugar, and baking powder. Mix wet ingredients with dry ingredients just until moistened. On a lightly, floured surface, roll dough into a 12" circle. Press into prepared pizza pan. Bake for seven minutes or until golden brown. Cool. Meanwhile, to prepare topping, combine powdered sugar and cream cheese. Spread over cooled cookie crust to within half inch of edge. Spoon cherry pie filling over cream cheese layer. Chill until ready to serve and then cut into wedges.