French Turbulence: Chocolate avocado macarons

This batch didn't turn out right. After nearly 2 weeks without baking macarons, being sick and taking care of a sick baby, I guess I was a little tired. But macaron baking is a science! So many things can go wrong and it is so easy to mess up. Macarons should have a smooth surface (that's why we sift the dry ingredients for the shells), have feet (that's why we let the raw shells rest before getting in a pre-heated oven), they should not be hollow (otherwise it means we incorporate too much air while folding the meringue into the dry ingredients), they shouldn't be too hard and crunchy (otherwise it means they baked too long), they shouldn't have cracks in the shells (otherwise it means there was too much moisture in the dough or in the oven), they shouldn't....
In a nutshell, macarons are not for the faints of heart. It's always good to have valium on hand when baking a batch.
This chocolate avocado batch didn't come out right. They tasted super yummy, but who cares if they were delicious wif they didn't have the right look! I am making macarons not whoopie pies.
However, I decided to come clean and bear it all out, right here.
My mistakes were a) to eye ball the amount of cocoa powder I threw in with the almond powder (I think I threw in 5 tablespoons instead of a modest 2), which gave me too much dry ingredients for the amount of meringue to mix with, and b) to bake 2 batches at once in my oven, which tends to increase the ambient moisture and create cracks in the shells.
This said, my husband thought they were delicious and the batch only lasted 2 days in the fridge...

Chocolate Avocado Macarons: (Macarons au Chocolat et au Beurre d'Avocat)

90g aged egg whites (about 3, aged on your kitchen counter 24 hours or longer)
110g almond meal
200g powdered sugar
30g granulated sugar
2 tablespoons unsweetened cocoa powder

zest of one lime
Avocado filling:

The flesh of 1 avocado, mashed

juice of one lime

2 tbsp softened butter

1/4 cup powdered sugar

pinch of salt

Sift together the almond meal and powdered sugar in a big bowl. Sift in the cocoa powder. You don't want any lumps in there.
In a separate bowl, beat the egg whites with an electric mixer. When they start foaming, throw in the granulated sugar and the zest. Beat on high until stiff peaks form.
With a rubber spatula, dump the egg whites in the almond mixture and FOLD gently until the dry ingredients and egg whites are well married. However, do not stir too much. Run a knife through. If the line disappears after ten seconds, stop folding.
Throw this paste in a large decorator bag (fitted with an Ateco #807 tip if possible) and pipe away on a silpat covered baking sheet. The macarons should be about 2 inches in diameter and 1 inch apart as they spread a little.
Let them rest for 20 to 30 minutes. Pre-heat your oven on 300F.
Bake the macarons for 18 minutes (keep an eye on them and you can give them a push with a finger to see if they are set). Let cool completely.

Prepare the avocado butter by blending together the mashed avocado, lime juice, salt, sugar and butter until smooth.
Spread a layer of avocado butter on a shell and cover with another shell. Repeat with all shells and refrigerate overnight to allow the filling to harden and the flavors to marry.