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

In a large mixing bowl, combine softened butter, brown sugar, and granulated sugar. Beat until creamy and fluffy, about 2-3 minutes.

Add the eggs one at a time, mixing well after each addition for 1-2 minutes.

Stir in the canned pumpkin puree and vanilla extract until well-blended.

In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, pumpkin spice blend, and salt. Gradually add to wet ingredients, mixing just until combined.

Fold in the semi-sweet chocolate chips and mini marshmallows using a spatula.

Drop rounded tablespoonfuls of dough onto the prepared baking sheets, spacing them about 2 inches apart.

Bake for 10-12 minutes until the edges are golden brown and the centers remain soft.