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

In a medium bowl, whisk together all-purpose flour, unsweetened cocoa powder, baking powder, and salt.

In a large mixing bowl, beat together granulated sugar, brown sugar, and eggs until light and fluffy. Add vanilla extract and mix.

Gradually add the dry ingredient mixture to the wet ingredients while mixing on low speed until just incorporated.

Transfer the dough to a covered bowl and refrigerate for about 30 minutes.

Mix granulated sugar with ground cinnamon in a small bowl for coating.

Scoop portions of dough, roll into balls, and coat each in the cinnamon sugar mixture. Place on the baking sheet.

Bake for 10-12 minutes until the edges are set and tops are slightly cracked.

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