Boil water and pour over oats. Let cool. Cream together sugars and shortening. Add eggs.
Sift (oat flour really needs to be sifted) in dry ingredients. Add oats.
Bake in a 9x13-inch pan at 350 °F for 30 minutes.
Notes
Oat flour works really well.
Substitutions
Can sub a safe oil for the shortening.
Any egg replacer will probably work well.
Egg Substitutions: There are many egg-free products and foods available to make your recipes free of eggs. Find out more about egg substitutions.
Gluten: Gluten is a protein found in specific grains (wheat, spelt, kamut, barley, rye). Other grains are naturally gluten-free but may have cross-contact with gluten-containing grains. Look for certified gluten-free products if you need to avoid gluten. Find out more about wheat and gluten substitutions.
Milk and Soy Substitutions: Alternative dairy-free milk beverages and products will work in most recipes. Find out more about milk substitutions and soy substitutions.