• Line an upside down pan with a silicone baking mat and fit a piping bag with a small #12 Wilton round tip, then set them both aside.
• In a medium bowl, sift the almond meal and powdered sugar into a larger bowl and discard any large pieces. Set aside.
• In a stand mixing bowl, add the egg whites and begin whisking on medium speed (speed 3-4) for 1-2 minutes. When the whites get foamy, add the cream of tartar.
• Very slowly, begin adding the sugar by the spoonful, sprinkling it into the whites as they whip. When all of the sugar is added increase the speed to medium (speed 4-5) and whip for about 4 minutes, then add 2 drops of the food coloring. Continue mixing for another 2-3 minutes, or until stiff peaks form.
• Add the whipped egg whites to a large bowl.
• Add ⅓ of the almond meal/sugar mixture to the whites. Fold very gently with a spatula until combined. Continue until all of the dry ingredients are incorporated.
• Using your rubber spatula, scrape the batter against the side of the bowl. Every few scrapes, pick up the batter and let it fall into the bowl. The batter should flow slowly in a continuous ribbon. Try to make a figure 8 with the batter. If it falls without breaking, it's ready.
• Fill your piping bag with the batter. Pipe directly over the top of the baking tray. Then drop the pan on the counter a few times to release any air bubbles. Use a tooth pick to pop any bubbles that come to the surface.
• Allow the shells to sit out to dry and form a skin. This can take anywhere from 30 minutes to an hour depending on the level of humidity in your house. They are ready to bake when the shell can be touched without it sticking to your finger or leaving an impression.
• While the shells rest, preheat your oven to 300 degrees F/149 C. (If your oven is on the hotter side a lower temperature might be better ie: 275-285)
• Bake each tray for about 12-14 minutes. The shells are done baking when you can gently touch the top of the shell and it barely budges from the foot. Let the tray cool completely on a wire rack before removing the shells and filling.

Making the Buttercream

• In a stand mixing bowl, add the soft butter and mix on medium low speed until smooth, about 1-2 minutes.
• Add the powdered sugar in a little bit at at time, mixing well after each addition. Scrape down the bowl with a spatula, then whip on high speed for 30 seconds until the buttercream is light and fluffy.
• Add the brown sugar, flour, and chocolate chips and mix on low until combined.

Assembling

• Fill a piping bag fitted with the same small round tip with the buttercream.
• Pipe a dollop onto one half of the shells and then sandwich the filling with the other half.
• Melt the dark chocolate chips in a bowl then add the coconut oil. Dunk the top of the shells in the chocolate and then sprinkle them with the crushed cookie pieces.
• Keep in the fridge in an airtight container overnight or at least for 12 hours to mature and soften.