Beat together the butter and sugar until creamy. Add the egg, vanilla, and sour cream and beat again.
Sift together the flour, baking powder, salt. Slowly add to the butter mixture until mixed in. Spread in a greased 9x13 glass dish. Set aside.
Beat the cream cheese and sugar until creamy. Add the egg and beat again.
Spread the cheesecake and pie filling in alternating lines over the top of the cake batter in the pan.
Mix together the topping ingredients and sprinkle over the top of the pie filling and cheesecake. Bake at 350°F for 50-60 minutes, or until a toothpick comes out mostly clean. Cool.
Mix together the powdered sugar and lemon juice and drizzle over the top of the cake. Cut into 24 squares. Store in a sealed container in the refrigerator.