- 300 grams aquafaba
- 175 grams granulated sugar
- 375 grams confectioners' sugar, divided
- 200 grams almond flour
- 1/ 2 teaspoon cream of tartar
- 150 grams vegan butter, room temperature
- 100 grams vegetable shortening
- 40 milliliters warm water
- 1 tablespoon vanilla bean paste
In a saucepan over low heat, combine the aquafaba and granulated sugar. Simmer for 12 minutes until it has reduced by about one third. Transfer the mixture into a stand mixer bowl and allow to cool for 1 hour.
Sift together the almond flour and 175 grams of confectioners' sugar a few times. Add the cream of tartar to the aquafaba and begin mixing on medium speed for 10 minutes. Once it reaches stiff peaks, gently fold in the dry mixture until you get a shaving cream consistency. A spatula dipped into the mixture should form a ribbon when pulled out. Transfer the batter into a piping bag with a round 1/2 inch piping tip and pipe circle discs onto a silicon mat. To achieve the Christmas tree effect, pipe 5 discs increasing by 1/2 inch in size.
Preheat an oven to 250ºF (120ºC). Tap the tray on a table a few times to pop all the bubbles. Leave the macarons to dry for at least 1 hour. After 1 hour, gently touch them to check that they are dry enough. If they are still tacky wait 30 minutes more.
Bake macarons for 40 minutes. Turn the oven off and leave the oven door open to allow the macarons to dry out.
Make the vanilla buttercream. Cream the butter and shortening in a stand mixer with the paddle attachment until pale and fluffy.
In a separate bowl, whisk together the remaining 200 grams of icing sugar with the hot water until smooth. Pour through a sieve into the creamed butter along with the vanilla bean paste.
Cream together for another 5 minutes then transfer the buttercream into a piping bag. Stack the macaron shells into Christmas tree towers, piping vanilla buttercream between each layer.