Finely grind the pistachios in a food processor or blender until fine. Add the powdered sugar and almond flour and process on low until the mixture is coarse. Then sift the mixture through a seive into a mixing bowl.
In a separate bowl, at high speed, beat eggs whites until they begin to foam. Continually beating, slowly add the drops of gel food coloring until reach desired color. Then slowly pour in the sugar and beat just until stiff peaks form.
Add about half of the sifted pistachio flour mixture into the egg white mixture and gently fold in with a spatula. Once incorporated, add remainingflour mixture and continue to gently fold until well the mixture flows like honey.
Transfer the batter to the preparing piping bag. Pipe the batter forming about 1½ inch circles. Space the macarons about an inch apart.
Pick up the baking sheet and drop onto a flat surface. Repeat 3-4 times to release all air bubbles rotating the baking sheet.
Let the macaron shells sit at room temperature for at least 30 minutes to 1 hour, until the macarons shells form a glossy layer. (You will be able to run your finger along the top of the macaron smoothly and the batterwon’t stick to your hand.)
Preheat the oven to 325F.
Bake the macarons for about 12 minutes, until the macarons form feet and the shells don't stick to the parchment paper.
Allow the macarons to cool before removing them from the parchment paper for easier removal.
Meanwhile combine butter and cream cheese in a bowl. Mix until creamy, add the powdered sugar and pistachios and mix. Add the heavy whipping cream and mix until combined. Transfer the filling into a piping bag with a round top.
Pipe the cream onto a macaron shell and top with another shell to form a sandwich.
Repeat with the remaining macaron shells and buttercream.
Place in an airtight container for 24 hours allowing them to mature.
This recipe will make a total of about 28 macarons, 56 macaron shells.
We love using macaron boxes for packaging and even for gifting!