01 -
In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt. In a large bowl, cream together butter, granulated sugar, and brown sugar until light and fluffy. Beat in the egg and vanilla. Gradually add the dry ingredients, mixing until just combined.
02 -
Drop dollops of peanut butter over the chocolate dough. With a knife or skewer, gently swirl the peanut butter into the dough to create marbled patterns. Avoid overmixing to maintain distinct swirls.
03 -
Cover the bowl with plastic wrap and refrigerate the dough for at least 1 hour.
04 -
Preheat the oven to 175°C (350°F). Line baking sheets with parchment paper. Scoop tablespoonfuls of dough onto the sheets, spacing them 5cm apart. Bake for 10-12 minutes, or until the cookies are set but still soft in the center.
05 -
Allow cookies to rest on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.