Preheat oven to 350 degrees
Cream together flour, softened butter and powdered sugar. Press evenly into bottom of ungreased 13x9 inch pan. Bake for 20 minutes.
Beat remaining ingredients until light, about 3 minutes. Pour over hot crust and bake about 30 more minutes or until no imprint remains when touched lightly in the center. Cool and cut into 2 inch square pieces. Sprinkle with powdered sugar on top.
Karen Ketter gave Mitzi this recipe when the Willis family lived in Tulsa Oklahoma in 1979. Karen was a neighbor of the family and called Amanda her junior brownie scout, even though she was only 9 months old.