Preheat oven to 350°F. Line two baking sheets with parchment paper or silicone baking mats.

In a medium bowl, sift together the flour, cocoa powder, baking soda, cinnamon, cardamom, and salt. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), beat the butter, brown sugar, and molasses until light and fluffy, about 3 minutes. Scrape down the bowl as needed.

Add the egg and vanilla, mixing until smooth and fully incorporated.

Gradually add the dry ingredients to the wet mixture, mixing on low speed just until a dough forms. Avoid over-mixing.

Scoop the dough with a #40 cookie scoop (about 1 ½ tablespoons each). Roll each dough ball in granulated sugar and place 2 inches apart on the prepared baking sheets.

Bake for 12–14 minutes, rotating the pans halfway through, until the cookies are set around the edges but still soft in the centers.

Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.