Preheat your oven to 300°F (150°C) and prepare your work area by lining two baking sheets with parchment paper.

In a bowl set over a double boiler, whisk the egg whites and granulated sugar together until frothy and dissolved, about 3-5 minutes.

Sift together the almond flour, cocoa powder, and powdered sugar in a separate bowl.

Gently fold the dry ingredient mixture into the meringue using a spatula until smooth and glossy.

Transfer the macaron batter into a piping bag and pipe small circles onto the prepared baking sheets.

Bake the Chocolate Peanut Butter Macarons in the preheated oven for 13 minutes.

While the macaron shells are cooling, prepare the filling by mixing softened butter and peanut butter until creamy.

Once the macaron shells are completely cool, pipe a dollop of filling onto one shell and create a sandwich.

Optionally, dust your assembled macarons with cocoa powder or powdered sugar.