1.

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

2.

In a large bowl, cream together the butter, granulated sugar, and brown sugar until the mixture is light and fluffy.

3.

Add the eggs one at a time, beating well after each addition, then stir in the vanilla extract thoroughly.

4.

In a separate bowl, whisk together the flour, baking soda, baking powder, and salt until well combined.

5.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined and forming a dough.

6.

Stir in the chocolate chips, mini marshmallows, and chopped nuts until they are evenly distributed in the dough.

7.

Drop tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart to allow spreading.

8.

Bake in the preheated oven for 8-10 minutes, or until the edges are golden brown and centers are set.

9.

Let cookies cool on the baking sheets for a few minutes before transferring them to wire racks to cool completely.