Preheat your oven to 300°F (150°C) and line two baking sheets with parchment paper.

Combine room-temperature egg whites and granulated sugar in a heat-resistant bowl over a double boiler and stir until frothy and warm.

Whip the mixture with a stand mixer until stiff peaks form.

Sift almond flour, cocoa powder, and powdered sugar into another bowl, then fold into the meringue.

Transfer the batter to a piping bag and pipe 1.5-inch circles onto prepared baking sheets.

Let the piped shells rest for 30 minutes before baking.

Bake for approximately 13 minutes, then cool completely.

Whip unsalted butter and peanut butter until smooth, then mix in powdered sugar, vanilla, and salt.

Assemble the macarons by piping filling onto half of the shells and sandwiching with the other half.