Preheat oven to 350°F. Grease 15" x 10" jelly roll pan.
Combine flour, baking powder and salt in a medium size bowl and stir well.
In a large mixing bowl, using an electric mixer, beat sugar and butter until creamy. Beat in eggs and vanilla extract.
Add flour mixture 1 cup at a time, beating on lowest speed or stirring by hand. Stir in 1-⅓ cups morsels. Spread into prepared pan. Sprinkle with remaining ⅓ cup morsels.
Bake for 20 to 25 minutes or until top is golden brown. Cool in pan on wire rack. Cut into bars. Store tightly covered.