Preheat oven to 300° . Line 9"x13" baking pan with wax paper. Beat together first three ingredients. Add flour to wet ingredients, 1 cup at a time. Spread dough into lined pan using a wet knife or metal spatula. Smooth to even out dough and prick all over with a fork. Bake for 40-60 minutes (until pale golden color.) Take out of oven and sprinkle with remaining 1/4 cup sugar. Cut into 30 to 35 pieces while still hot. Cool in pan.