Begin by placing your mini marshmallows in the freezer for at least 2 hours before baking.

Preheat your oven to 350°F (175°C). Prepare a baking sheet lined with parchment paper.

In a medium bowl, whisk together the gluten-free flour, baking soda, and sea salt until well combined.

In a large bowl, beat the softened butter, granulated sugar, and brown sugar until smooth and creamy.

Add the creamy peanut butter, egg, and vanilla extract to the mixture and mix until combined.

Fold the frozen mini marshmallows into the batter using a spatula.

Gradually mix the dry flour mixture into the wet ingredients until just combined.

Shape the dough into balls weighing about 2-3 tablespoons and place them 1-2 inches apart on the baking sheet.

Bake for 10-11 minutes until edges are golden but centers are soft. Allow to cool on the baking sheet.

Transfer cookies to a wire rack to cool completely.