Sift together flour, baking powder, salt, cream of tartar and sugar three times. Add dry milk. Mix well. Cut in shortening with pastry blender or two knives until mixture looks like cornmeal. Store in covered container at room temperature.
NOTE: To measure the Master Baking Mix, pile it lightly into cup and level off with a table knife.
Biscuits, Preheat oven to 450° F. Combine 1 1/2 cups Master Baking Mix and 1/3 cup milk in a bowl. Add milk all at once, stirring 25 strokes. Knead lightly on floured board. Roll 1/2-inch thick; cut and place on ungreased baking sheet. Bake 10 minutes.
Options: Add grated cheese, chopped herbs. Increase milk to 1/2 cup for drop biscuits. Use as a topping on casseroles, cobblers or meat and vegetable pies.
Muffins, Preheat oven to 425° F. Beat together in a bowl 1 egg, 1 cup milk and 2 Tbsp sugar. Add 3 cups Master Baking Mix. Stir just until dry ingredients are moistened. Spoon into greased muffin pans and bake 20 minutes.
Options: Add drained fruit, chopped nuts or chopped dried fruit. Replace 1/3 cup of Master Baking Mix called for with quick-cooking oatmeal or All-Bran.Servings: 12 muffins