For the macaroon: Preheat oven to 350 degrees F (preferably convection). Make an Italian meringue by combining sugar and water in a saucepan over high heat until it’s 110 C (230 degrees F). At the same time, beat all the egg whites in the bowl of a stand mixer with a whisk attachment on medium speed. Meanwhile, mix the rest of the macaroon ingredients by combining almond flour and powdered sugar together. Make a well in the middle of the bowl and add all the egg whites. Mix by starting in the center and mixing towards the outside. Set aside. Finish the Italian meringue when the egg whites are at “soft peak” stage in the mixer by adding 1 teaspoon sugar and mixing 15 more seconds. Pour the heated sugar mixture into the beating egg whites, slowly to make the meringue. Continue beating until it’s at room temperature, 5 more minutes.
When the meringue is at room temperature, combine it with the almond paste mixture, a third at a time. Continue to add meringue until the batter forms ribbons. The mixture shouldn’t be too stiff or too loose and you may not need all of the meringue. Using the tip of a knife, add a small amount of food coloring, a little at a time. Place macaroon mixture into a piping bag and squeeze a little into the bowl to remove air at the tip. Prepare a baking sheet with parchment paper, then draw rings on the paper to use as guides for the macaroon size. Pipe onto the baking sheet by starting in the center and pushing up, staying inside the ring. Repeat until all of the rings are filled. Bake 12 minutes until shiny with a little “neck” on the outside.
For the buttercream: In a saucepan over high heat, add sugar and water and bring to a boil until thermometer reaches 120 degrees C. Meanwhile, place egg whites in the bowl of a stand mixer fitted with a whisk attachment and beat on high. When egg whites are firm and sugar syrup has reached 120 degrees C, slowly pour the sugar mixture into the egg whites and continue beating until it cools down to room temperature, 5 minutes. Slow down the mixer and add butter, a little at a time. If at any point the mixture looks broken, increase the speed and beat to re-emulsify it, then reduce the speed and continue adding the butter. Continue whipping until it’s the texture of butter cream. If the buttercream is too loose to hold it’s shape, it should be refrigerated for up to a few hours to harden, then beaten again to return to the proper consistency. Place 1 cup of butter cream into a bowl and fold in the jam. Place the buttercream into a piping bag with tip and pipe the cream onto the center of a macaroon (using the same technique as the macaroons). Sandwich together and enjoy. Note: The buttercream can be stored in a covered container in the refrigerator for up to 5 days or frozen for up to 1 month; defrost frozen buttercream in the refrigerator before using. Thirty minutes before using the buttercream, place it in the bowl of a mixer fitted with the paddle attachment and allow to soften. Then mix on low speed to return the buttercream to the proper consistency.