Chocolate Peanut Butter Macarons

Directions

1. 1
   Combine almond flour, powdered sugar and cocoa powder until well blended (I used my food processor). In the bowl of a stand mixer fitted with the whisk attachment, whip the egg whites on medium-high speed until foamy. Gradually add the granulated sugar and continue beating until a smooth, shiny meringue with stiff peaks forms. Add the ground almond mixture to the bowl with the meringue and quickly but gently fold together using a wide rubber spatula until no streaks remain. You want to achieve a thick batter that ribbons or flows from the spatula when lifted.
2. 2
   Line two baking sheets with silicone baking mats. Transfer the batter to a piping bag fitted with a plain wide round tip. Pipe into small rounds on the prepared baking sheets (each round should be about 1-11/2 inches in diameter), spaced about 1 inch apart. Let sit at room temperature for about an hour to develop a hard shell.
3. 3
   Preheat the oven to 300°F. Bake for 8-10 minutes, depending on size. Transfer the pans to a wire cooling rack and let cool completely before moving the cookies.
4. 4
   While the cookies are cooling, make the frosting. Stir together all the remaining ingredients until it is the right consistency. I always just add the milk at the end to get the texture I want. Put into a piping bag, fitted with a plain tip.
5. 5
   Once the cookies are cool, match them up so they are paired with one that is a like size. Squeeze some frosting onto the base, and place the top on. Gently press down. They are best eaten the next day.