Preheat oven to 375°. Beat butter at medium speed with an electric mixer until creamy. Gradually add 1 cup sugar, beating until mixture is smooth; add flour, beating until dough forms a ball.
Press dough into a 14- x 10-inch jelly-roll pan with floured hands.
Bake at 375° for 30 to 35 minutes or until golden brown. Cut immediately into 35 (2-inch) bars. Sprinkle with 2 Tbsp. sugar, if desired.