Chewy oatmeal chocolate chip cookies sandwiched together with a dreamy, creamy marshmallow filling in these oh so yum Choc-Oat-Chip Whoopie Pies.
- 1 cup (2 sticks) unsalted butter, softened
- 1/2 cup granulated sugar
- 1/2 cup dark brown sugar
- 1 large egg
- 1/2 teaspoon pure vanilla extract
- 1 cup all-purpose flour
- 1 cup quick cooking oats
- 1 (3.4 ounce) box vanilla instant pudding mix
- 1 teaspoon baking soda
- 1 cup chocolate chips
- 1/2 cup (1 stick) unsalted butter, softened
- 1 cup marshmallow fluff
- 3 cups powdered sugar
- 1–2 teaspoons milk, if needed
- Preheat oven to 350°F. Line two cookie sheets with parchment paper and set aside.
- In the bowl of an electric mixer, beat the butter and sugars until smooth. Add the egg and vanilla and beat until well combined.
- In a separate bowl, whisk together the flour, oats, dry pudding mix, and baking soda. Add the dry ingredients, 1 cup at a time, to the wet ingredients in the mixer until just combined.
- Stir in the chocolate chips. Shape dough into 2-tablespoon sized rounds and place a few inches apart on the prepared cookie sheets. Press additional chocolate chips into the tops of the cookies, if desired. Flatten each cookie very slightly with the palm of your hand.
- Bake for 10-12 minutes or until the cookies start to turn golden brown, rotating the cookie sheets after 6 minutes of baking.
- Let cool about 5 minutes on the cookie sheets and then transfer to a wire rack to cool completely.
- Meanwhile, make the filling. In the bowl of an electric mixer, fitted with the whisk attachment, beat together the butter and marshmallow fluff until smooth. Add the powdered sugar, one cup at a time, mixing on low speed at first until just combined and then on high speed until filling begins to fluff, about 2 minutes. If the filling is too thick, add one teaspoon of milk at a time until soft peaks form.
- Turn half of the cookies over and spread with the filling. Top with a similar size cookie.
Marshmallow fluff can be found in a plastic jar near the marshmallows at the store.
Store in an airtight container.