Beat butter and 3/4 cup powdered sugar at medium speed with an electric mixer until creamy. Add extracts, beating until blended. Gradually add flour, beating at low speed until blended. Press dough into an ungreased 15- x 10-inch jelly-roll pan.
Bake at 325° for 20 minutes or until golden. Cool in pan on a wire rack 10 minutes. Cut into squares; sprinkle with powdered sugar. Remove to wire racks to cool completely.