Step 1: Prepare the Dough

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Cream Butter and Sugars: In a large bowl, beat together the softened butter, granulated sugar, and brown sugar until the mixture is light and fluffy.
3. Add Eggs and Vanilla: Mix in the eggs, one at a time, followed by the vanilla extract, ensuring everything is well combined.

Step 2: Combine Dry Ingredients

1. Mix Dry Ingredients: In another bowl, whisk together the flour, cocoa powder, baking soda, and salt.
2. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Avoid overmixing to keep the cookies tender.

Step 3: Add Chocolate and Marshmallows

1. Incorporate Chocolate Chips: Gently fold in the chocolate chips and mini marshmallows (if using) until evenly distributed throughout the dough.

Step 4: Bake the Cookies

1. Scoop the Dough: Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheet, leaving space between each cookie.
2. Bake: Bake in the preheated oven for 10–12 minutes, or until the edges are set but the centers remain soft. The cookies will firm up as they cool.

Step 5: Cool and Serve

1. Cool the Cookies: Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.
2. Enjoy: Serve warm or at room temperature, and savor the deliciousness of your hot chocolate cookies!

Step 1: Prepare the Dough

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Cream Butter and Sugars: In a large bowl, beat together the softened butter, granulated sugar, and brown sugar until the mixture is light and fluffy.
3. Add Eggs and Vanilla: Mix in the eggs, one at a time, followed by the vanilla extract, ensuring everything is well combined.

Step 2: Combine Dry Ingredients

1. Mix Dry Ingredients: In another bowl, whisk together the flour, cocoa powder, baking soda, and salt.
2. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Avoid overmixing to keep the cookies tender.

Step 3: Add Chocolate and Marshmallows

1. Incorporate Chocolate Chips: Gently fold in the chocolate chips and mini marshmallows (if using) until evenly distributed throughout the dough.

Step 4: Bake the Cookies

1. Scoop the Dough: Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheet, leaving space between each cookie.
2. Bake: Bake in the preheated oven for 10–12 minutes, or until the edges are set but the centers remain soft. The cookies will firm up as they cool.

Step 5: Cool and Serve

1. Cool the Cookies: Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.
2. Enjoy: Serve warm or at room temperature, and savor the deliciousness of your hot chocolate cookies!