Prepare the oven and baking sheet: Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats. This will help prevent the cookies from sticking and make cleanup much easier.

Cream butter and sugars: In a large mixing bowl, beat together the softened butter, brown sugar, and granulated sugar using a hand mixer or stand mixer until light, fluffy, and well combined. This step ensures your cookies will have a soft, chewy texture.

Add eggs and vanilla: Crack in the eggs one at a time, mixing well after each addition. Then add the vanilla extract and continue to mix until the batter looks smooth and slightly glossy.

Mix dry ingredients: In a separate medium bowl, whisk together the flour, cocoa powder, baking soda, and salt until evenly combined. Slowly add this dry mixture to the wet ingredients, mixing on low speed until just combined. Do not overmix, as that can make the cookies tough.

Fold in s’mores mix-ins: Gently stir in the chocolate chips, mini marshmallows, and graham cracker chunks. Make sure the marshmallows and crackers are evenly distributed throughout the dough so every cookie has a gooey, crunchy surprise.

Shape and bake: Scoop out tablespoon-sized portions of dough and roll them into balls. Place them about 2 inches apart on the prepared baking sheets. The dough will spread as it bakes, so leave enough space. Bake for 10–12 minutes, or until the edges are set but the centers still look slightly soft.

Cool and set: Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack. The marshmallows will be gooey, so letting them rest helps the cookies hold their shape without falling apart.

Serve and enjoy:

Once fully cooled, arrange the cookies on a plate or platter. They’re best enjoyed warm when the chocolate and marshmallows are still melty, just like a campfire s’more.