These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie’s Oatmeal Creme Pies with their super soft texture and creme filling – but they have a peanut butter twist!

These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie's Oatmeal Creme Pies with their super soft texture and creme filling - but they have a peanut butter twist!

There are few things more nostalgic than a Little Debbie’s Oatmeal Creme Pie. That soft, spiced oatmeal cookie, the sweet marshmallow creme squishing out the sides with every bite…it’s a lunchbox classic for a reason. But they’re also way more processed than most things I like to bake, so I made my own version and did what I do to most things: added peanut butter. These Peanut Butter Oatmeal Sandwich Cookies are softer, more flavorful, and filled with a marshmallow creme frosting that my friends declared should be “put on everything.” They’re everything you loved about the original, just better.

What Are Peanut Butter Oatmeal Sandwich Cookies?

These are a homemade, peanut butter-spiked take on the Little Debbie’s Oatmeal Creme Pie. You get the same soft, spiced oatmeal cookie and sweet marshmallow creme filling that made those little snacks so iconic, but with a peanut butter kick running through the cookie and none of the ultra-processed ingredients. They’re nostalgic, a little indulgent, and easy to make.

These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie's Oatmeal Creme Pies with their super soft texture and creme filling - but they have a peanut butter twist!

Why You’ll Love This Recipe

  • Crowd favorite every time. These are the kind of cookies that disappear fast and always get requested again.
  • Pure nostalgia! All the soft, spiced, marshmallow-filled charm of a Little Debbie’s Oatmeal Creme Pie, made from scratch with real ingredients.
  • Peanut butter makes everything better. The cookies have a nice peanut butter kick that adds depth and makes them way more interesting than the original.
  • The filling is dangerously good. Marshmallow Fluff whipped with butter and powdered sugar comes together in minutes and tastes like a fluffy cloud.
  • Easy to make ahead. The dough keeps in the fridge for up to a week, so you can bake fresh cookies whenever the craving hits!
These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie's Oatmeal Creme Pies with their super soft texture and creme filling - but they have a peanut butter twist!

Ingredients and Key Components

The oatmeal cookies are made with quick oats, all-purpose flour, brown sugar, cinnamon, and a generous scoop of creamy peanut butter. The combination of brown sugar and butter keeps them soft and slightly chewy, and the cinnamon adds that warm, cozy flavor you expect from a classic oatmeal cookie.

The marshmallow creme filling is just Marshmallow Fluff, butter, powdered sugar, vanilla, and a pinch of salt, whipped together until light and fluffy. My friends declared it “frosting that should be put on everything,” and I completely agree. It comes together in a couple of minutes and tastes like a cloud.

These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie's Oatmeal Creme Pies with their super soft texture and creme filling - but they have a peanut butter twist!

Tips for the BEST Cookies

Chill the dough. This step is important. Chilling the dough for at least 2 hours (and up to a week) helps prevent the cookies from spreading too much in the oven and helps develop flavor. It’s a great make-ahead option if you want to bake them off fresh later.

Watch them closely in the oven. You want to pull these when the centers are just barely past dough, and the edges are only slightly golden. Overbaking is the enemy of a soft, squishy sandwich cookie. They’ll look underdone, but they firm up as they cool.

Match your cookies by size before filling. Before you start spreading the marshmallow creme, pair up cookies of similar size so each sandwich looks neat and the filling is evenly distributed.

Don’t overfill. About a tablespoon of filling per sandwich is the sweet spot. Enough to get that satisfying squish when you bite in, but not so much that it all escapes out the sides.

These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie's Oatmeal Creme Pies with their super soft texture and creme filling - but they have a peanut butter twist!

Make-Ahead and Storage

The cookie dough keeps in the fridge for up to a week, so you can make it ahead and bake when you’re ready. The assembled sandwich cookies keep at room temperature in an airtight container for up to 3 days, or in the fridge for up to a week. The filling actually softens the cookies a little as they sit, which makes them even better on day two.

These Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling are reminiscent of Little Debbie's Oatmeal Creme Pies with their super soft texture and creme filling - but they have a peanut butter twist!
Rachel Conners

Peanut Butter Oatmeal Sandwich Cookies with Marshmallow Creme Filling

No ratings yet
Print Recipe Pin Recipe
Prep Time: 30 minutes
Cook Time: 10 minutes
Total Time: 40 minutes
Servings: 12 sandwich cookies

Ingredients
 

  • 1 stick (½ cup) unsalted butter, softened
  • ¾ cup light brown sugar, firmly packed
  • ¼ cup granulated sugar
  • 1 tablespoon vanilla extract
  • ½ cup creamy peanut butter
  • 1 large egg
  • ¾ cup quick oats
  • 1 cup all-purpose flour
  • ½ teaspoon baking powder
  • ½ teaspoon baking soda
  • ½ teaspoon cinnamon
  • ½ teaspoon salt

For the marshmallow cream

Instructions
 

  • In large bowl, cream together butter, brown sugar, and white sugar until light and fluffy. Beat in vanilla extract and peanut butter. Beat in egg until well blended.
    1 stick (½ cup) unsalted butter, ¾ cup light brown sugar, ¼ cup granulated sugar, 1 tablespoon vanilla extract, ½ cup creamy peanut butter, 1 large egg
  • Combine oats, flour, baking powder, baking soda, cinnamon, and salt. Add into peanut butter mixture and beat until just combined.
    ¾ cup quick oats, 1 cup all-purpose flour, ½ teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon cinnamon, ½ teaspoon salt
  • Chill cookie dough, covered, at least 2 hours and up to 1 week.
  • Preheat oven to 350 degrees F. Form rounded tablespoons of dough into balls and arrange about 2 inches apart on baking sheets lined with parchment paper.
  • Bake cookies in batches in middle of oven for 10 to 11 minutes, or until just pale golden. Cool cookies on baking sheet 5 minutes and transfer to racks to cool completely.
  • While cookies are cooling, prepare marshmallow buttercream filling.

For the filling

  • Combine all ingredients in large bowl and mix on high speed with an electric mixer for 1 to 2 minutes or until light and fluffy.
    7 oz. jar Marshmallow Fluff, ½ cup (1 stick) unsalted butter, ⅓ cup powdered sugar, 1 tablespoons vanilla extract, ⅛ teaspoon salt
  • Match cookies in pairs based on size. Spread 1 tablespoon of buttercream onto one cookie and sandwich with other cookie in the pair. Repeat until all cookies are sandwiched.

Notes

Recipe originally published on Delish.
Did you make this recipe?Please consider Leaving a star rating and review!