Pistachio Macarons

Directions

1. 1
   To make the macaron shells, place the egg whites in the bowl of a stand mixer fitted with a whisk attachment. Whip the egg whites until they begin to foam, about 2 minutes. Slowly add the sugar to the egg whites while the mixer is still going. You might need to stop the mixer and scrape down the sides of the bowl a couple times. Continue to whip the egg whites until stiff peaks have formed.
2. 2
   While the egg whites are whipping, combine the powdered sugar, almonds and pistachios in a food processor and pulse until the nuts are finely ground. If you cannot get the nuts to grind finely enough, sift the mixture and then pulse again.
3. 3
   Once the nuts are finely ground, add the mixture to the whipped egg whites. Fold the egg whites quickly at first to break up some of the air. Then continue to fold the mixture carefully until the batter flows like a thick ribbon. It should take no more than 50 folds for the batter to reach the right consistency.
4. 4
   To color the shells, add a few drops of the food coloring (I prefer to use gel or powdered food coloring so as to not add any extra water to the batter). If desired, add more coloring to make the color more concentrated.
5. 5
   Put the batter into a piping bag fitted with large round tip (I used Ateco #808). Pipe small rounds of the batter onto a baking sheet that you've lined with a silicone mat (parchment paper works too). The rounds should be no larger than 1.5 inch in diameter. Be careful to not pipe the rounds too close to each other-give space for them to spread.
6. 6
   Let the macaron shells sit for at least 30 minutes, until their shells are hardened. Preheat the oven to 280 F. Once at least 30 minutes have passed, place the macaron shells in the oven and bake for about 12 minutes (until the shells have rosen and are hardened).
7. 7
   Cool the macarons on the baking sheets.
8. 8
   While the macarons are cooling, make the buttercream filling. Cream the butter in the bowl of a stand mixer fitted with the whisk attachment until light and fluffy, about 5 minutes.
9. 9
   Add the confectioner's sugar and salt and mix (gradually increasing in speed) until the sugar is fully incorporated, about 5 minutes. You may need to stop the mixer and scrape down the sides of the bowl a couple times.
10. 10
    Add the vanilla and whisk until the mixture is light and fluffy, about 3 minutes. Once the buttercream is creamy and airy, the buttercream is done!
11. 11
    Once the macaron shells have cooled, match the macaron shells in pairs. Place each pair next to each other, with one of the shells topside down.
12. 12
    Put the buttercream into a piping bag fitted with medium sized round tip. To fill the macarons, pipe a small round of buttercream on the macaron shell that its top side down. Top the filling with the other matching macaron shell (top side up). Repeat with the remaining macarons.
13. 13
    Serve and enjoy!
14. 14
    These last up to 2 days in a sealed container.
15. 15
    Macaron recipe adapted from Tartelette.