Thin Crispy Oatmeal Cookies

These thin and crispy oatmeal cookies are the kind of cookies everyone keeps reaching for. They’re light, crunchy, and full of oatmeal flavor, with those lacy edges that get extra crisp as they cool. The easy one-bowl dough comes together with simple pantry ingredients, no chilling, and no special equipment. Flatten them thin, let them cool, and you’ll have cookies that kids and adults can’t stop reaching for, perfect with a glass of milk for the kiddos or a cup of coffee for the big bellies.

If you love these cookies and are looking for other fun, healthy cookie recipes that incorporate oats, be sure to try out these carrot oatmeal cookies, copy-cat nutter butter peanut butter cookies, and these easy maple syrup chocolate chip cookies.

What You’ll Need

Here is what you’ll need to make these thin crispy oatmeal cookies:

• Rolled Oats: I love baking with rolled oats as they are packed with nutrition! Gluten-free rolled oats make these cookies gluten-free.
• Oat Flour: Oat flour acts as the main dry “binder.” It absorbs moisture from the wet ingredients and helps the cookies hold together.
• Egg: Used as a binder to help hold the cookies together.
• Maple Syrup: The main source of sweetness for these cookies.
• Oil: For added moisture and flavor in the cookies
• Vanilla Extract, Cinnamon, Salt: For added flavor and that classic cookie taste.
• Baking Soda: Helps the cookies spread and brown.

See the recipe card below for full information on ingredients and quantities.

Ingredient Substitutions & Additions

• Oat Flour: You can make your own by blending rolled oats into a fine flour.
• Oil: Any neutral oil works, like avocado or light-tasting olive oil. I used coconut oil to add a slight coconut flavor, but stick with a neutral oil if you don’t want hints of coconut. I don’t recommend using butter because oil helps them stay thin and crunchy since it contains no water.
• Maple Syrup: Honey can be used, but cookies may brown slightly faster. I prefer maple syrup because it gives the cookies a nice caramel-like taste, but honey will also work.
• Egg: You may replace the egg with a flax egg. Note that the cookies will be slightly less crispy with a flax egg. To make one flax egg, combine 3 tablespoons of water with 1 tablespoon of ground flaxseed. Let the mixture sit in the fridge for about 15 minutes until it forms a gel-like texture. 
• Add-Ins: Chocolate chips, raisins, or chopped nuts are great add-ins for added flavor and crunch. Be careful with adding too many since they may affect the crispiness of the cookies. We love drizzling melted chocolate on top!

Step-by-Step Instructions

STEP 1: In a medium bowl, whisk together the maple syrup, oil, egg, and vanilla until smooth and well combined (Images 1 & 2).

STEP 2: Add the oat flour, rolled oats, cinnamon, baking soda, and salt to the bowl. Stir until the dough is fully combined (Images 3 & 4).

STEP 3: Scoop tablespoon-sized portions of dough onto the prepared baking sheet at least 1 inch apart. (Image 5).

STEP 4: Use your fingers, the back of a spoon, a spatula, or parchment paper to flatten each cookie as thin as possible. This step is very important because the thinner the cookies, the crispier the texture will be (Image 6).

STEP 5: Bake for 13–15 minutes, or until the edges are deep golden brown. Allow the cookies to cool completely on the baking sheet. They will continue to crisp up as they cool.