Gluten Free Leftover Oatmeal Muffins

Why You'll Love This Leftover Oatmeal Muffins Recipe

This oatmeal muffin recipe is adapted from my old standby The Fannie Farmer Cookbook. Fannie Farmer was the one who guided me through my first baking attempts and can still be relied upon for a good, basic chocolate cake, blueberry muffin, or, in this instance, a recipe that is the epitome of "waste not, want not". This leftover oatmeal muffin recipe calls for simple, real ingredients: nothing fancy, nothing strange.

• Great use of leftovers. If your kids are like mine, they may seem hungrier in the morning than they actually are! We always seem to have a bit of oatmeal leftover in the pot. I love tucking it into this batter so it doesn't go to waste!
• Sturdy and satisfying. Packed with whole grain oats and oat flour, these muffins are a filling snack that hold up well in lunchboxes.
• So adaptable. I actually love leftover oatmeal muffins plain as I've outlined in this post, but it's also fun to pop in chocolate, nuts, fruit, and more! You can use this recipe as your jumping-off place for all sorts of add-ins.

Ingredient Notes

See the recipe card at the end of this post for the full ingredient amounts.

• Oat flour - Learn how to make oat flour, pick up a bag, substitute a store-bought or homemade gluten free flour blend, or use sorghum or brown rice flour for the oat flour.
• Granulated sugar - If you wish for less sweet muffins, reduce the sugar by ¼ cup or substitute ⅓ cup maple syrup for the sugar.
• Baking powder - To help the muffins rise - check that your baking powder is fresh!
• Salt - I use fine grain sea salt and table salt also works.
• Milk - Whole milk or 2% milk works fine.
• Egg - Use a large egg.
• Butter - Use unsalted butter or melted coconut oil
• Cooked oatmeal - I always use old-fashioned rolled oats for oatmeal, but you can also use steel-cut oats or quick-cook oats. Any kind of cooked oatmeal you have on hand will do!

Leftover Oatmeal Muffins Variations

I show the muffins plain here so you get an idea of what they look like, but I love to dress them up a little bit, too! Add-ins can include:

• Chocolate - Try 1 cup of dark or milk chocolate chocolate chips.
• Fruit - Add 1 cup of fresh or frozen blueberries or raspberries! Dried fruit like cherries, raisins, or cranberries is also nice.
• Nuts - Stir 1 cup of chopped, toasted walnuts to the batter before baking.
• Brown sugar - For a more caramel, deeper note of sweetness, substitute light brown sugar for the granulated sugar.

Try my gluten free oatmeal raspberry muffins next!

Leftover Oatmeal Muffins Tips & Substitution Suggestions

• Rest the batter - Gluten-free baking always benefits from a rest before a batter or dough is baked so that the flour can hydrate. Let the muffins rest in the tin while the oven preheats for the best results. Read my gluten-free baking tips.
• Oat flour substitute - You can swap almond flour or sorghum flour, another whole grain gluten-free flour, for the oat flour.
• Make them dairy-free - These muffins easily can be made dairy-free if needed! Substitute melted coconut oil for the melted butter, and your favorite non-dairy milk for the milk.
• Make them refined sugar-free - Instead of brown sugar, you can use maple syrup, honey, or coconut sugar.
• Make them vegan - Follow the dairy-free substitutions listed above, and leave out the egg.

Serving Suggestions

Salted butter is seriously the best on a warm leftover oatmeal muffin! I don't go overboard here, but you could add cream cheese, unsalted butter, non-dairy butter, or a little peanut butter. A cup of coffee or tea alongside is also lovely.

How to Store Leftover Oatmeal Muffins

• Counter - Place leftover oatmeal muffins in an airtight container and keep them on the counter up to 3 days.
• Fridge - Store the muffins in their container in the fridge for up to 5 days.
• Freezer - Place the muffins in a freezer-safe bag and keep them in the freezer for up to 3 months. Thaw in the fridge before eating.
• To Reheat - A light toast in the toaster oven will warm these muffins up beautifully. Or, pop them in the microwave for 30 seconds.