Line two large baking sheets with parchment paper or a silicone mat. Preheat the oven to 300 F/150 C.
Sift the almond meal and powdered sugar into a bowl. Set aside.
In a stand mixing bowl, whisk together the egg whites and powdered sugar. Place it over a pot of boiling water. Whisking occasionally, bring the temperature to 120 F/48 C.
Attach the bowl to a stand mixer with the whisk attachment and add the cream of tartar. Whisk on medium speed for 5-7 minutes until it cools down. Once at a soft peak, add the food coloring. Increase the speed again, mixing until stiff peaks form, then run the mixer on the lowest speed setting for 1-2 minutes to even out the meringue bubbles. Do not take the speed faster than a #6 on a Kitchen Aid!
Add the dry ingredients to the meringue all at once and gently fold them in with a rubber spatula.
Fold and scrape the batter against the sides of the bowl. When it starts to look glossy, pick up some of the batter and let it fall off the spatula into the center of the bowl. Count to 30; if the edges of the ribbons are very soft and mostly disappeared into the batter, it’s ready.
Fill a piping bag with a small round tip with the batter and pipe it onto the prepared baking pans. Each round should be about 1 ½ inches wide spaced 2 inches apart. Gently tap the edges of the pan on the counter, with quarter turns in between taps. Pop any large bubbles with a toothpick, then sprinkle the tops with the sprinkles.
Bake the first tray straight away after piping, for 18-20 minutes. When they stop wiggling, bake for another two minutes. Then let the pan cool on a wire cooling rack. At this point, you can pipe the rest of the batter on the second tray and bake right away.
While the macarons cool, make the buttercream. Combine the butter and powdered sugar in a mixing bowl until smooth. Then add the clear vanilla extract, almond extract, heavy cream, and sprinkles. Mix on medium-high speed for 2-3 minutes until very light and fluffy.
To assemble; match up like-sized shells. Pipe a dollop of buttercream on half of the shells, then sandwich the filling with the other shells.
Place the filled macarons in an airtight container and mature them in the fridge overnight to soften the texture. Enjoy!
Notes
*Measure your flour properly. This is my #1 baking tip! Do not ever scoop a measuring cup into your flour as this always leads to using too much flour. Instead, use the spoon-level method. This means fluffing the flour first, then spooning it into your measuring cup/spoon. For the BEST results, use a kitchen scale!*Use gel food coloring. I recommend using gel or powdered food coloring for best results.Baking times may vary. All ovens are different, and your macarons may bake quicker or take longer than the indicated baking time. You may also need to adjust the temperature as needed, 275 F-325 F is a good range for baking macarons.Once baked and filled, store them on a tightly wrapped tray or in an airtight container in the fridge for up to 1 week.They will get hard in the fridge because the butter is re-solidifying. Take them out and let them come to room temperature to soften before enjoying.