For the macarons

1. Start by weighing out graham crackers and sugars. Grind graham crackers in a food processor until very fine.
2. Sift graham crackers and powdered sugar together, making sure there are no lumps.
3. Whip egg whites with a pinch of cream of tartar in mixer on medium speed until foamy. Once foamy slowly add granulated sugar in a steady stream while mixer is on.
4. Scrap down sides of bowl to ensure all sugar is incorporated.
5. Turn mixer on high and whip egg whites until stiff glossy peaks form. Do not overbeat.
6. Add 1/3 of dry ingredients at a time to egg whites. Folding the batter gently by hand with a spatula. Continue until just combined, careful not to over mix. The batter should fall from the spatula in thick ribbons and resemble a slow lava like flow.
7. Pipe macaron batter into small circles on a cookie sheet lined with parchment paper. Carefully slam trays down on the counter to help release any air bubbles.
8. Let macarons sit on the counter for 30-45 min until a skin forms and the batter no longer sticks to your finger when touched.
9. While macarons are resting heat oven to 375 degrees F.
10. Bake one sheet at a time for 10-13 minutes. Tops of shells should be firm and the center should barely jiggle from the “feet”. Let cool on a wire rack in the pan for 2 minutes, then remove parchment paper with cookies off the pan and leave on rack until fully cooled.

Marshmallow Buttercream

1. Whip butter until light and fluffy.
2. Add in vanilla extract then slowly add in confectioners sugar.
3. Add marshmallow creme and whip until fully combined.

Chocolate Ganache

1. Chop chocolate into small pieces.
2. Heat cream and corn syrup over medium heat until cream is just boiling.
3. Remove from heat and add in chocolate, stirring until melted.
4. Stir in butter.
5. Let sit at room temperature or in the fridge until ganache has set and is a solid consistency for piping.

To assemble

1. On one half of the shells pipe on marshmallow buttercream.
2. Repeat with chocolate ganache on other half of shell.
3. Gently press the two sides together.
4. Place sandwich cookies in the fridge for the fillings to set.