Chocolate Peanut Butter Burgers (French Macaroons)

Ingredients

• 0.5 cup butter at room temperature
• 2.5 tablespoons cocoa powder 
• 1 cup confectioners' sugar 
• 2.5 cups confectioners' sugar 
• 5  egg whites 
• 1.5 cups plus 1 tablespoon ground almonds 
• 0.5 cup peanut butter at room temperature
• 0.3 teaspoon vanilla extract 

Equipment

• bowl
• frying pan
• baking paper
• oven
• whisk
• blender
• pastry bag

Directions

1. Special equipment: Pastry bag with round tip
2. Make the Macaroons: Preheat the oven to 300 degrees F.
3. Line several sheet pans with parchment paper and set aside. In a bowl, combine 2 1/2 cups of the sugar, almonds, and cocoa powder.
4. In another clean dry bowl whip the egg whites with the remaining 1/2 cup sugar until medium peaks form (do not beat to stiff peaks). Fold egg whites into dry ingredients to a make a meringue. Fill the pastry bag with the meringue. (To easily fill the pastry bag, place it (with a clothespin holding it shut at the bottom) in a tall round container such as a coffee can, mayonnaise jar, or vase, folding the edge over the rim of the container.)
5. Pipe rows of kisses 1-inch in diameter (about the size of a quarter), keeping them 1/2 inch apart, onto the sheet pans.
6. Bake until very light brown, rotating the pans after 8 minutes, about 17 minutes.
7. Let the macaroons cool on the pan.
8. Meanwhile, make the Peanut Butter Buttercream: In a standing mixer fitted with a whisk attachment, cream the butter until light and fluffy.
9. Add the peanut butter and whip.
10. Add the confectioners' sugar and vanilla and whip until fluffy.
11. Transfer the buttercream to a clean pastry bag fitted with a round tip.
12. Peel 2 macaroons off the parchment, pipe the buttercream on 1 flat side and sandwich the other flat-side down on top. Repeat with the remaining macaroons. Keep chilled in an airtight container until ready to serve.