01 -
In a mixing bowl, stir together the salt, baking soda, flour, and cocoa powder. In a separate larger bowl, blend the butter, both sugars, and vanilla until fluffy. Crack in the egg and mix. Slowly incorporate the dry mixture, stirring until combined.
02 -
Place spoonfuls of peanut butter on top of the dough. Use a skewer or knife to create a marbled look by swirling the peanut butter around. Be careful not to overdo it—keep the swirls visible.
03 -
Wrap the dough bowl with plastic film and set it in the fridge for a minimum of one hour.
04 -
Start by warming the oven to 350°F (175°C) and placing parchment paper on baking sheets. Drop tablespoon-sized mounds of dough onto the sheets. Let them bake for 10 to 12 minutes, until they're set but still feel soft.
05 -
Leave the cookies on the hot baking tray for 5 minutes. Then, move them onto a wire rack to finish cooling completely.