Imagine your favorite soft and chewy oatmeal cookie recipe with natural peanut butter flavor. Add some vanilla buttercream filling in between and roll the sides in chopped peanuts. Meet your new favorite sandwich cookie recipe!
The only thing better than freshly baked Peanut Butter Oatmeal Cookies are making two into a sandwich cookie!
Creamy vanilla filling makes this dessert an exciting treat anytime.
Perfect for Back-to-School, weekend snacking or a special surprise ‘just because’.
Peanut Butter Oatmeal Cookies
These soft-and-chewy inside and light crisp on the outside cookies are always a favorite.
This dessert recipe is a two-for-one. You can make the delicious cookies and stop there.
OR you can whip up the easy vanilla buttercream filling and create a one-of-a-kind sandwich cookie.
You can also stop THERE or roll the sides in chopped peanuts for a peanut butter lovers dream recipe.
It also could be rolled in mini chocolate chips!
The ingredients for this cookie recipe are probably in your pantry and refrigerator right now!
There’s nothing exotic, just wholesome baking basics. The star ingredients include:
Peanut Butter – use creamy peanut butter for the best result.
Old Fashioned Oats – don’t use Instant Oats. Rolled oats are whole oats and add a different texture to the cookie recipe.
Unsalted Butter – there is some both in the cookies and the filling. We’ve broken it out in the recipe card below to keep it straight forward.
How to Make it Gluten-Free
Use a gluten-free measure-for-measure flour blend. My recommendation is Bob’s Red Mill Gluten-Free 1-to-1 Baking Flour for the best results.
Also use clearly labeled gluten-free rolled oats.
Everything else is naturally gluten-free.
How to Make It – Step-by-Step
STEP 1: Preheat the oven to 350 degrees F. Line a rimmed baking sheet with parchment paper (unless it is non-stick).
STEP 2: In a large bowl (or bowl of a standing mixer) combine the butter, granulated sugar, peanut butter, and brown sugar (photos 1-3). Beat until light and fluffy (photo 4).
STEP 3: Add the egg and vanilla extract; beat until combined (photos 5-7).
STEP 4: In a small bowl whisk together the flour, baking soda and salt (photo 8).
STEP 5: Add half the dry ingredient mixture to the batter, beat together until fully combined (photo 9). Repeat with the remaining flour (photo 10). Stir in the oats (photo 11).
STEP 6: Make balls 1 1/2 to 2 inches in diameter. TIP: using a cookie scoop makes this fast, easy and uniform cookie sizing.
Place on the cookie sheet (photo 12) and bake for 8-10 minutes until the tops are set. Cool on the baking sheet 5 minutes then transfer to a wire rack to cool completely (see photo 13).
Making the Filling
STEP 7: Beat the butter until light and fluffy. Add the powdered sugar 1/2 cup at a time (photos 13-14) mixing between additions (note the mixture will appear crumbly).
STEP 8: Add the vanilla and cream; beat until the icing forms (photo 15).
Making the Sandwich Cookies
STEP 9: After the cookies are completely cooled, spread filling on the bottom of one cookie and place the flat side of a second cookie on top of the filling to form a sandwich (photo 16).
NOTE: this can be done by spreading the filling on with or piping it for a more decorative look (refer to the printable recipe card below).
If desired roll the sides of the filling in chopped peanuts.
How to Store
Cookies: Store in a sealed container on the counter top for up to 4 days.
They can be stored up to a week in the refrigerator but tend to get hard. If chilling them allow the cookies to warm on the countertop before eating.
Assembled Sandwich Cookies: The assembled sandwich cookies can also be stored in an airtight container at room temperature.
American Buttercream (the type of filling) does not need to be refrigerated provided it’s not a very hot, humid environment. Then it will melt.
Another option is to keep the filling in a separate container in the refrigerator and assemble the cookie sandwiches ‘on demand’.
More Dessert Recipes You’ll Love!
- Carrot Cake Cookies
- Ginger Pear Pie Recipe
- Apricot Crumble
- Eggnog Snickerdoodles
- Raspberry Cheesecake Cookies
- Lemon Chiffon Pie
Peanut Butter Oatmeal Sandwich Cookies
- 8 tablespoons (1 stick) Unsalted butter softened
- 1/2 cup Light brown sugar packed
- 1/3 cup Granulated sugar
- 1/2 cup Creamy Peanut Butter
- 1 Egg
- 1 teaspoon Vanilla extract
- 3/4 cup All purpose flour regular or gluten-free measure-for-measure flour blend
- 3/4 teaspoon Baking soda
- 1/4 teaspoon Salt
- 1 cup Old fashioned oats regular or gluten-free
- 12 tablespoons (1 1/2 sticks) Unsalted butter softened
- 2 1/2 cups Confectioner's (powdered) sugar
- 1 teaspoon Vanilla extract
- 1 tablespoon Heavy whipping cream
- Optional : 1/2 cup finely chopped peanuts OR mini chocolate chips to roll the edges of the cookie in
Making the Cookies
- Preheat oven to 350 degrees F. Line cookie sheet with parchment paper or use a non stick cookie sheet.
- In a large bowl, beat the butter, brown sugar, granulated sugar and peanut butter until light and fluffy.
- Add in the egg and vanilla, mixing until combined.
- In a small bowl, whisk together the flour, baking soda and salt.
- Add half of the flour mixture into the wet ingredients and beat until combined. Add the remaining flour and mix again.
- Stir in the oats.
- Form balls 1 1/2 to 2 tablespoon in size, or use a cookie scoop for better uniformly sized cookies. Place on a cookie sheet 2 inches apart.
- Bake for 8-10 minutes, just until the tops are set. Allow the cookies to cool on the baking sheet for five minutes. Then place them on a wire cooling rack to cool completely before making the sandwich cookies.
Prepare the filling
- Using a hand mixer or stand mixer, beat the butter for a few minutes until it has become light and fluffy.
- Slowly add in the powdered sugar, 1/2 cup at a time, and continue mixing in between each addition. The mixture will appear very crumbly at this point.
- Add in the vanilla and heavy cream and continue mixing until the texture changes and the icing has formed.
To Assemble Sandwich Cookies (pick one of the following two methods)
- OPTION 1: Spread the icing onto a bottom of a cookie (flat side) and top it with another cookie flat side facing the filling.
- OPTION 2: For a fancier ook, fill a piping bag with the icing and use a 1M tip for a ruffled effect. Or cut the tip of the bag off (no tip required) and pipe the icing through the cut end.
Optional Nuts around the Filling outside
- To coat the exterior of the filling with nuts, prepare a cookie sandwich. Roll the edges in a bowl of nuts.