Directions for Shells
1. Place 55 grams egg whites in bowl of stand mixer. Start whisking on low.
2. Place 55 grams egg whites in separate bowl. Add food coloring and whisk to combine.
3. Sift almond flour and powdered sugar into a large bowl.
4. Prepare the Italian meringue. Place water in small pot over medium heat. Add the granulated sugar. Without stirring, cook on medium until 115 C / 239 F, or when bubbles slowly break the surface.
5. Increase speed on mixer to high. The egg whites should be just starting to form peaks as the sugar syrup reaches 118 C/ 244 F. Pour the hot syrup into the whisking egg whites, as the mixer is going. Continue to whisk on high for one minute. Reduce speed to medium and continue to whisk for 4-5 minutes, until the mixture cools slightly to 50C/122F.
6. Meanwhile, prepare piping bags and use a rubber spatula to incorporate the dyed egg whites to the powdered sugar/almond mix. Add a quarter of the meringue to the almond mix and stir it in to lighten the mixture. Add the remaining meringue and fold it in until the mixture is incorporated, starts to shine, and slowly falls off the spatula when lifted.
7. Transfer mixture to a piping bag with an 11-pt tip. Pipe according to the template on a silplat-lined baking sheet. Once a full sheet of macarons of have been piped, pick up the baking sheet and drop it on a table from about 5 inches. Let the shells sit undisturbed for 2 hours. Preheat oven to 325F.
8. Once the shells are no longer wet (if you lightly touch them with your finger, they should feel dry), bake them in a 325F oven for about 12 minutes. After the first 8 minutes, open the oven door slightly, and then close it. Repeat this step after 10 minutes. Once the macaron shells are cooked, remove the pan from the oven, and transfer it to a cooling rack. After about 10 minutes, remove the macaron shells from the lined pan. (If you don’t remove them, they may end up sticking.)
Directions for Filling
1. Add the sugar and eggs to a large glass bowl. Whisk to combine. Whisk in the passion fruit puree and lemon juice. Place the bowl over a pot of simmering water. The bowl should not touch the water. Whisk continuously until the mixture thickens and reaches 165F on an instant-read thermometer. Remove the bowl from on top of the pot and immediately pour the curd through a strainer into a medium-sized bowl. (The strainer will strain out any curdled bits.)
2. Let the mixture sit for 10 minutes. Stir in the softened butter. Use an immersion blender and blend for 2 minutes, until the mixture is creamy and smooth. Cover the mixture with plastic, touching the cream, and allow to set in the refrigerator for at least 3 hours.
3. Once the cream is set, assemble the macarons by piping the filling in the center of half of the macaron shells. Place a shell on top of each. Refrigerate overnight, which allows the filling to set. Remove from the refrigerator about 10 minutes before serving. The macarons should be served at room temperature.