Preheat your oven to 350°F (175°C).

In a medium bowl, whisk together the gluten-free flour, baking powder, salt, and cocoa powder.

In a separate large bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy, about 2-3 minutes.

Add the egg and vanilla extract to the butter mixture and mix until well combined.

Gradually add the dry ingredients to the wet ingredients, stirring until just combined.

Scoop out tablespoon-sized portions of dough and roll them into balls. Place them on the prepared baking sheet, spaced about 2 inches apart.

Create a small indentation in the center of each ball and fill it with chocolate hazelnut spread.

Bake for 10-12 minutes until edges are set and centers remain soft. Let cool for a few minutes on the baking sheet.

Press a chocolate chip into the center of the hazelnut spread on each cookie, then place a mini marshmallow on top.

Allow cookies to cool completely on a wire rack.