Mix sugar, brown sugar, and molasses in a bowl. It’s fine if it’s clumpy and not perfectly mixed together. Set aside.
Whisk or sift together the flour, cocoa powder, salt, and baking soda. Set aside.
Cream the butter for 2-3 minutes until light and very creamy.
Add the sugar mixture and mix another 2-3 minutes, scraping down the sides of the bowl.
Add the egg and vanilla. Mix until combined.
Add the flour mixture, and mix until just combined, scraping down the sides of the bowl if necessary. Try not to over mix the dough. It should be very thick and fudgy.
Add the chocolate chunks, chips, and optional nuts, mix until combined.
Chill dough in the fridge for at least 30 minutes.
While dough is chilling, preheat oven to 325 ℉.
Once dough is chilled and the oven has pre-heated, drop 1.5-2 tablespoons of dough at a time on a parchment or silicone mat lined baking sheet, keeping the balls of dough 1-2 inches apart.
Baking 10-12 minutes until firm around the edges. Watch closely, since they’re so dark it can be easy to burn or over bake.
Let cool before removing from the baking sheet. They will be very soft at first, but firm up as they cool. Enjoy!