Preheat oven to 350F. Place 1 cup sugar in food processor; blend 30 sec. (or use fruit sugar). Add to softened butter and cream mixture until very fluffy.
Combine flour and rice flour. Beat into batter in small portions. Turn batter out onto a lightly floured surface. Knead until smooth, adding up to 1/2 c more all-purpose flour, if needed. Press into a 15 x 9 jelly roll pan. Score into bars with a sharp knife. Prick surface with fork. Sprinkle with remaining 2 T sugar. Bake 10 minutes then lower heat to 300F and bake until golden, about 30 to 40 minutes. Cut along scored lines, cool and store in air tight container.
