These gluten-free peanut butter oatmeal cookies are incredibly thick, soft, and chewy thanks to natural peanut butter, melted butter, and a blend of alternative flours: oat, sweet rice, and tapioca. Packed with hearty rolled oats and (optionally) bittersweet chocolate chunks, they’re quick to mix up in one bowl with zero chilling required, taking just 30 minutes start to finish.
Several readers have asked if my oat and rice flour oatmeal cookies could be made with peanut butter. The answer? It’s complicated.
Natural peanut butter (the kind that uses only peanuts) looks and feels like a wet ingredient. But it’s actually very low in water and high in protein, which makes it act more like a dry ingredient. When I added it into my cookie recipe, instead of spreading and puffing, the cookies baked up overly thick with a dry, chalky texture.
To solve the natural peanut butter problem, I swapped out some of the flour and tweaked the liquid ratios. After testing (and eating!) many (many!) batches, I hit on the perfect balance for a cookie that stays soft and tender for days.
This reader feedback made me smile:
5-Star Reader Review – Delicious!
“To say these cookies are delicious is an understatement. I followed the recipe as written and will again and again and again. Thanks for a fantastic cookie (GF or not!)”
—Linda
These cookies bake up thick, loaded with hearty oats, big peanut butter flavor, and a kiss of flaky sea salt. I love stirring in dark chocolate chunks for peanut butter cup vibes, but they’re equally delicious made sans chocolate, allowing the floral notes of vanilla to shine. They would also be incredible sandwiched with my salt-kissed natural peanut butter icing for the ultimate oatmeal cream pie.
And if you need an entirely grain-free version of these, try my bakery-style almond flour peanut butter cookies instead.
A Few Ingredient Notes
- Peanut butter: My go-to brand is Once Again Organic which is silky smooth and fresh-tasting. I like to store unopened jars upside-down so it’s easier to stir in the oil once opened.
- Oats: Be sure to grab old-fashioned rolled oats that are certified gluten-free. I usually toast my oats to build flavor in cookies, but when I was shooting these images, I accidentally dumped in raw oats. This turned out to be a good thing because I learned that the peanut butter adds enough flavor here, so it’s fine to skip this step.
- Flour power: Skip the bland all-purpose blend and grab 3 bags of flour for these cookies: oat flour for earthy flavor and tenderness, sweet rice flour for structure, and tapioca flour for softness and chew. You can find substitutions and more recipes in my guide to baking with alternative flours.
Stir, Scoop, Bake, Yum
Bojon appétit! If you’re hungry for more, check out my award-winning gluten-free baking cookbook Alternative Baker or subscribe to my free, spamless newsletter to hear from me every week or so.
Soft, Chewy Gluten-Free Peanut Butter Oatmeal Cookies
These gluten-free peanut butter oatmeal cookies are incredibly thick, soft, and chewy thanks to natural peanut butter, melted butter, and a blend of alternative flours: oat, sweet rice, and tapioca. Packed with hearty rolled oats and bittersweet chocolate chunks, they’re quick to mix up in one bowl with zero chilling required, taking just 30 minutes start to finish.
Servings: 14 cookies
Ingredients
Wet Ingredients
- 8 tablespoons (113 g) unsalted butter, melted
- ½ cup (100 g) packed light brown sugar
- 2 tablespoons (25 g) organic granulated sugar
- 1 large egg (about 50 g out of the shell)
- ½ cup (120 g) creamy, natural peanut butter (I use Once Again brand)
- 1 teaspoon vanilla extract
Dry Ingredients
- ¼ cup + 2 tablespoons (38 g) gluten-free oat flour
- ¼ cup (39 g) sweet rice flour
- ¼ cup (28 g) tapioca flour
- ½ teaspoon fine sea salt
- ½ teaspoon baking soda
- 1 cup (100 g) gluten-free old-fashioned rolled oats
- Oats and flaky salt for sprinkling (optional)
Chocolate Version
- 5 ounces (140 g) coarsely chopped bittersweet chocolate or chocolate chips (60-70% cacao mass)
Instructions
Make the Cookie Dough
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Place the brown and granulated sugars in a large bowl. Stir in the hot melted butter and let cool for a few minutes.
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Whisk in the egg until smooth, then whisk in the peanut butter and vanilla.
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TIP: be sure to whisk in the egg first and then the peanut butter, otherwise the mixture may not emulsify and the cookies will be grainy.
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Place a mesh strainer over the bowl and sift in the sweet rice, oat, and tapioca flours, baking soda, and salt. Stir to combine, then stir in the oats and chocolate (if using) until combined.
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Let the dough sit for 10-20 minutes until thick enough to scoop.
Bake the Cookies
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Form the dough into balls that are about 2 ½ tablespoons large (a #24 cookie scoop works well).
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Place the dough balls on the prepared cookie sheets, spacing them 2-3 inches apart.
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Top each dough ball with a pinch of oats and flaky salt.
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Bake the cookies at 350ºF until the edges are just starting to set and the centers are puffed and wet to the touch, 8-10 minutes.
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TIP: Natural peanut butter is especially sensitive to overbaking, so be extra careful not to overbake these or they will turn crumbly and have a dry mouthfeel.
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Remove the cookies from the oven and pull them, parchment and all, onto wire racks to cool. They will be delicate at first but will continue to firm up as they cool.
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Store the cookies at room temperature for up to 8 days.
Notes
While many of my drop cookie recipes can be scooped into balls and refrigerated until ready to bake, I found that these cookies are best baked shortly after mixing the dough. When I stashed the dough balls to bake off later, the cookies didn’t spread enough, and even when flattened first, they baked up pale and on the dry side. I much preferred these cookies baked off right away and stored at room temp, where they stay just as soft and tender as the day of baking.
