The apple buttercream filling in these is absolutely amazing.
180 g almond flour
240 g powdered sugar
140 g egg whites, aged
2 g fine sea salt
80 g sugar
Separate the egg whites at least 24 hours to making this recipe, leaving them covered in the fridge. This helps remove moisture and increase acidity which will help create a fuller and more stable meringue.
Preheat the oven to 300F and cut 2-3 pieces of parchment paper to fit on baking sheets. Prepare a piping bag with a small round tip (a 10 works well) and set aside.
Combine the powdered sugar, almond flour and salt in a medium bowl and set aside.
Whip the egg whites until frothy, then begin slowly sprinkling in the sugar and whip to stiff peaks, or until the meringue doesn't slide in the bowl when tipped.
Sift the dry ingredients into the egg whites and fold until well combined and shiny. You want the mixture to spread slightly, but not be too runny.
Pour the macaronage into the prepared piping bag and pipe the macarons in small rounds onto the parchment. Bake them for about 8 minutes, rotate the sheetpan and bake for another 8 minutes or until the tops *just* slide over the feet.
You could definitely use store bought apple butter for this, but we had a lot of apples laying around after a trip to the orchard and I wanted to use them up. The benefit of making it at home is that it makes your house smell wonderful.
1 lb 9 oz apples (I used a mix of Mutsu and Empire. I don't know that they're the best for this application, but it's what I had and I think it worked well)
2 c water
1 tbls lemon juice
1/4 tsp salt
1 tbls honey
1 stick cinnamon
10 allspice berries
1/4 tsp ground nutmeg
Peel and dice the apples.
Place the prepared apples and remaining ingredients in a large pot. Bring to a boil over high heat, then reduce the heat and let simmer until very soft, about 2 hours. Be sure to mix every once in awhile, increasing the frequency with which you do so the longer the apples cook. Once very soft and caramelized, remove from heat and allow to cool briefly before picking out whole spices and pouring into a blender or food processor to puree. Store in the fridge.
Apple Swiss Meringue Buttercream
3/4 c sugar
3 egg whites
9 Tbls buter, softened
3/4 tsp vanilla
In a double boiler, cook the egg whites and sugar, whisking constantly, until sugar is dissolved. Remove from heat and whip (with a stand mixer or an hand-held one) until room temp, about ten minutes. Lower speed and begin adding the butter, piece by piece, waiting until each cube is incorporated before adding the next. After all butter is added, return mixer to high speed and beat until the buttercream comes together. Add the apple butter to taste and use to fill the macarons.