Preheat oven to 300°F. Line two baking sheets with parchment paper. Set aside.
Heat a small pot of water over medium heat until it steams. In the bowl of a stand mixer, combine egg whites and granulated sugar. Place bowl over steaming pot, creating a double boiler.
Whisk egg whites and sugar until sugar melts completely and egg whites become white and frothy, 1 to 1.5 minutes. Remove from heat and place bowl back onto standing mixer.
Fit standing mixer with whisk attachment and whisk on high speed for 2-3 minutes, until stiff peaks form. Congratulations, you just made a Swiss meringue!
Sift together almond flour, cocoa powder, and powdered sugar, then gently shake into meringue bowl.
Place bowl onto stand mixer fitted with a whisk attachment. Turn mixer to medium speed and whisk for 10 seconds. Stop mixer and use a spatula to scoop up some of the batter. If you can make a figure-eight with the dripping batter without the batter breaking, you can stop. But most likely you will need another 5-10 seconds. So repeat process, and try the figure-eight again. The best way to describe the perfect consistency is like slow moving lava. It should give, but only slightly, like in slow-motion.
Once your batter is the correct consistency, scoop it into a large pastry bag fitted with a 1 inch tip. Pipe silver dollar-sized circles onto prepared baking sheets, keeping about 1.5 inches between each meringue. Bang baking sheet on counter two times to remove any air bubbles.
Here’s the fun part: you don’t need to let them air dry. Just pop them into the prepared oven for 13 minutes, turning around halfway through, then allow to cool completely before removing from baking sheets.
While the macarons are baking, make the peanut butter filling. Beat together the peanut butter and butter until combined. Add the powdered sugar, vanilla extract, and salt and beat until fluffy.
Scoop mixture into a piping bag fitted with a star tip and set aside until ready to assemble the macarons.
Once you’re ready, pipe the ganache onto a macaron and sandwich with another macaron. Repeat with all macarons. Optional: garnish with melted chocolate and chopped up peanuts for some added texture!
Tips for Chocolate Peanut Butter Macarons
Make sure you’re using almond FLOUR and not almond meal. Almond meal is usually coarser and made from almonds that have not been blanched.
Because the meringue in this is a swiss meringue (meaning it’s cooked slightly), you don’t need to let these macarons dry out before putting them in the oven!