1️⃣ Preheat oven to 325°F (163°C). Line two baking sheets with parchment paper.
2️⃣ Cream butter, brown sugar, and granulated sugar together for 2–3 minutes until light and fluffy.
3️⃣ Add egg and vanilla; mix to combine.
4️⃣ Add molasses and mix on low until smooth.
5️⃣ In a separate bowl, whisk flour, cocoa powder, baking soda, and salt.
6️⃣ Add dry ingredients to wet in 3 additions, mixing just until combined.
7️⃣ Scoop dough into 1.8–2 oz (large tablespoon-size) balls.
8️⃣ Roll each dough ball in granulated sugar.
9️⃣ Place 2–3 inches apart on baking sheets.
10️⃣ Gently flatten cookies using your palm or flat bottom of a measuring cup — do not over-flatten.
11️⃣ Sprinkle a little extra sugar on top and bake 10–11 minutes until edges are set and tops crack.
12️⃣ Cool on baking sheet 10 minutes before transferring to a rack.