1. Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.

2. In a large bowl or stand mixer, cream butter with granulated sugar and brown sugar on medium-high speed for 3-4 minutes until light and fluffy.

3. Beat in eggs one at a time, mixing 30 seconds after each. Add vanilla extract and mix until incorporated.

4. In a separate bowl, whisk together flour, cocoa powder, baking soda, salt, and cinnamon.

5. Add dry ingredients to butter mixture in two additions, mixing on low speed just until no flour streaks remain.

6. Fold in chocolate chips until evenly distributed throughout the dough.

7. Use a 2-tablespoon cookie scoop to portion dough into balls. Arrange 2 inches apart on prepared baking sheets.

8. Bake for 10-12 minutes, rotating pans halfway through. Cookies should be set at edges but soft in centers.

9. Let cookies cool on baking sheet for 5 minutes, then transfer to wire rack to cool completely.

10. Once cooled, place cookies back on baking sheet. Top each with one large marshmallow, flat-side down.

11. Return to 350°F oven for 2-3 minutes until marshmallows puff and turn golden. Watch carefully to prevent burning.

12. Remove from oven and gently press each marshmallow down slightly with the back of a spoon.

13. Optional: melt chocolate chips and drizzle over cooled, topped cookies.

14. Let marshmallow-topped cookies cool completely before storing or serving.