Heat oven to 350ºF. Butter spingform pan, 9x3 inches, or 9-inch square pan. Mix 1 1/2 cups flour and the brown sugar in medium bowl. Cut in butter, using pastry blender or crisscrossing 2 knives, until crumbly. Reserve 1/2 cup mixture for topping. Press remaining mixture on bottom and 1 1/2 inches up side of pan. Bake 15 minutes or until golden brown and set.