01 -
Microwave the butter in a large bowl until melted. Stir in the sugar, then microwave again for 30 seconds. Stir and microwave once more for 60 seconds until the mixture bubbles slightly but does not burn.
02 -
Stir the chopped bittersweet chocolate into the hot butter mixture until completely smooth. If needed, microwave for an additional 15 seconds. Let cool for 5 minutes.
03 -
Add the eggs and vanilla extract to the cooled chocolate mixture. Whisk until glossy and smooth.
04 -
Add the flour, cocoa powder, and salt. Stir with a spatula until just combined and no flour streaks remain. Do not overmix.
05 -
In a small bowl, mix the peanut butter, softened butter, and powdered sugar until smooth. Warm for 15 seconds in the microwave if too stiff. Drop small spoonfuls over the brownie batter.
06 -
Use a knife to drag the peanut butter dollops into loose figure-eights. Bake at 350°F for 40 minutes, or until a knife inserted in the center comes out with a few moist crumbs. Cool before slicing.