These homemade oatmeal cream pies cookies are soft and chewy with a rich, creamy marshmallow frosting filling. A nostalgic childhood treat better than Little Debbie!
Preheat the oven to 350°F and line baking sheets with parchment paper. Set aside.
Combine the butter, brown sugar and granulated sugar in a large mixing bowl. Beat on medium speed until creamy. Add in the egg and vanilla and beat until free of lumps.
In a separate bowl, combine the flour, baking soda, baking powder, salt, cinnamon and nutmeg. Mix well. Gradually add to the butter mixture and mix just until combined. Stir in the oats until combined.
Using a small cookie scoop or Tablespoon, drop the cookie dough onto the baking sheet about 2-inches apart. Bake in the preheated oven for 7-8 minutes, or until lightly golden around the edges, while the center is still slightly soft.
Remove from oven and allow to cool on the pan for a couple minutes. Transfer the cookies to a cooling rack. Allow to cool completely.
Marshmallow Frosting:
Combine the butter, powdered sugar, marshmallow creme and vanilla in a large bowl. Mix with beaters until smooth and creamy. Add more powdered sugar if needed. Place frosting in a zip top bag. Then snip off the end to frost the cookies.
To make cookie sandwiches, frost the bottom of one cookie and place another cookie bottom on top. Store in an air tight container.
Notes
If making cookie sandwiches, use a small cookie scoop or roll into a 1-inch ball. If serving singular cookies with frosting on top, I prefer to use a medium cookie scoop.