Sift together dry ingredients; cut in shortening till mixture resembles coarse crumbs. Add milk all at once; stir only till dough follows fork around bowl. Turn out on lightly foured surface; knead gently 1/2 minute.
Roll in a 16 x 12 inch rectangle, 1/4 inch thick; brush with butter. Combine 1/3 cup sugar and cinnamon; sprinkle over surface. Cut in eight 12 x 2 inch squares.
Grease muffin pans or line with paper bake cups. Pressing layers together slightly, place square, cut side down, in pans. Bake in hot oven (425°) 10 to 12 minutes or till done. Makes one dozen.