Prepare the marshmallows by placing them in the freezer for at least 1-2 hours before baking.

Preheat your oven to 350°F (175°C) and line two baking sheets with silicone mats or parchment paper.

In a medium bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, and ½ teaspoon of salt.

In a large mixing bowl, cream together ½ cup of room temperature unsalted butter, ½ cup of granulated sugar, and ½ cup of light brown sugar until light and fluffy.

Add 1 cup of creamy peanut butter, 1 large egg, and 1 teaspoon of vanilla extract. Mix until combined.

Gradually add the dry ingredients and mix on low speed until combined.

Fold in the frozen mini marshmallows until evenly distributed.

Use a #30 cookie scoop to portion the dough onto the prepared baking sheets, spacing them a few inches apart.

Bake for 11-12 minutes or until just set with lightly browned edges.

Cool on baking sheets for about 10 minutes before transferring to a wire rack.