S'mores Macarons

To make the Macarons:

1. In a food processor, combine the powdered sugar, almond flour, and graham crackers. Process until completely fine.
2. In a stand mixer fitted with a whisk attachment or using a handheld mixer, beat the egg whites until thickened. Add the granulated sugar and continue to beat until stiff peaks form.
3. Gently fold the beaten egg whites into the ground almond and graham cracker mixture until combined, but be careful not to overmix. It should be the consistency of “molten lava” but not runny, about 40-65 folds.
4. Transfer the batter to a piping bag fitted with a 0.4 inch (10 millimeter) circular tip.
5. On a parchment lined baking sheet, pipe 1 1/2 inch (4 centimeter) circles at least 2 inches (5 centimeters) apart. Repeat with remaining baking sheets.
6. Firmly tap the baking sheets against the counter to remove excess bubbles. Allow to rest uncovered 30-40 minutes to form a shell.
7. Preheat oven to 300˚F (150˚C).
8. Bake the macarons in preheated oven until the tops become firm, 15-20 minutes. Allow to cool before removing from baking sheet.

To make the Milk Chocolate Ganache:

1. Pour cream into small saucepan over medium heat. Right before coming to a boil, remove from heat and add the chocolate chips. Allow to rest for 30 seconds before mixing until smooth.
2. Transfer to a small bowl, cover, and refrigerate, whisking occasionally, until firm enough to pipe.

To make the Marshmallow Buttercream:

1. In a large bowl, beat together the butter and marshmallow fluff until smooth. 
2. Slowly beat in the powdered sugar. Beat in just enough milk to make a smooth and light marshmallow buttercream. Refrigerate until needed.

To assemble:

1. Pair the cooled macaron shells based on the closest matched shapes.
2. On the bottom of one of the shells, pipe a small dollop of chocolate ganache, then another dollop of the marshmallow buttercream.
3. Gently cover with with bottom of the other macaron shell. Lightly press together until the chocolate reaches the edges. Repeat with remaining pairs.
4. Refrigerate in single layers for 24 hours and up to a week. Bring to room temperature for 1 hour before serving.