Preheat oven to 425 degrees F. Grease 12 muffin cups with shortening. Sift flour with salt & baking powder into mixing bowl. Cut in shortening with pastry blender until mixture looks like coarse crumbs. Add milk all at once. Mix just until dough follows fork around the bowl. Turn out onto a lightly floured surface. Knead gently for 30 seconds. Roll into a 12x7-inch rectangle. Spread thinly with softened butter. In a small mixing bowl, combine sugar & cinnamon. Sprinkle dough with cinnamon mixture. Roll up tightly, starting with the long side. Seal by pinching the dough with your fingers. Cut into 1-inch slices. Place 1 slice in each muffin cup. Bake for about 15 minutes or until lightly brown. If desired, frost with Powdered Sugar Glaze.
In a mixing bowl, stir together 1 cup sifted powdered sugar, 1/4 tsp. vanilla & 1 - 1 1/2 tbs. milk to make frosting of drizzling consistency.
Yield: 12 cinnamon rolls