Filling: In another large bowl, beat cream cheese until smooth. Add eggs and vanilla and beat until well blended. Beat in the melted butter until evenly blended. On low speed, gradually beat in the box of powdered sugar. Continue to beat until mixture is smooth.Spread the cream cheese mixture over crust in pan. Bake for 40-50 minutes or until sides are set and center is still a little jiggly. Remove from oven and cool completely. Dust with powdered sugar and cut into squares. Serves 20