1-First, sift together the powdered sugar, almond flour, cocoa powder, and espresso powder for the macaron shells. This helps remove any lumps and mixes the flavors evenly.

2-Next, whisk the egg whites and granulated sugar over simmering water until they get frothy, then beat them until stiff peaks form. This step uses the Swiss meringue method for better stability, which is key for those perfect, airy shells.

3-Gently fold the dry ingredients into the egg white mixture until the batter is glossy and flows smoothly. Remember to test the batter consistency by piping a small sample before baking to avoid issues like spreading too much.

4-Pipe the batter into 1.5-inch circles on lined baking sheets and let them rest until a dry skin forms on top. This resting period is crucial for that smooth finish.

5-Bake at 300°F (about 150°C) for 16-20 minutes, rotating the trays halfway through. You can adjust to 325°F if your oven runs cool, and practice will help you nail this step.

6-For the frosting, cream the butter, cream cheese, and peanut butter together until smooth. Gradually add the sifted powdered sugar and vanilla extract, mixing well, and add milk if needed for the right consistency.

7-To assemble, pipe the peanut butter cream cheese frosting onto one chocolate espresso shell and sandwich it with another. Optionally, add extra frosting and crushed peanuts on top for a fun twist.