Beat butter, sugar, eggs and vanilla at medium speed about two minutes until light and fluffy.
Combine flour, baking powder and salt, adding gradually to creamed mixture. Beat well.
Spread in greased 11x15" jelly roll pan, saving about 1-1/2 c. batter for topping.
Spread cherry pie filling over dough to edges of pan.
Spoon rest of dough over cherries.
Bake at 350 degrees for 45 minutes.
Sprinkle with powdered sugar before serving. Cut in squares.