Prepare a macaron template by using a large piping tip or small round cookie cutter of about 1 ½″ in size to trace circles about 2 inches apart on one sheet of parchment paper. You will place this under another piece of parchment paper when ready to pipe the macaron shells.
In a medium bowl, sift the almond flour and powdered sugar twice. Set aside.
In a small heat-proof bowl, whisk together the egg whites and granulated sugar. Place the bowl over a small saucepan of simmering water, and whisk often until the sugar has dissolved or until the temperature is about 120 degrees F.
Transfer the egg white mixture to the bowl of a stand mixer fitted with a whisk attachment. Whisk until the mixture reaches soft peaks. At this point, you can add the vanilla. Continue whisking the meringue until stiff peaks form.
Divide the meringue evenly between two bowls, about 95g each. Divide the dry ingredients between the same two bowls, about 124g each. Add 10 drops of red food gel to one bow, and 10 drops of blue food gel to the other.
Start the macaronage by using a rubber spatula to scrape around the sides of the bowl, then through the middle of the batter.
Once the dry ingredients are fully incorporated, begin spreading the batter along the sides of the bowl to deflate it slightly. Continue scraping around the sides of the bowl and through the middle. The mixture is ready when you can draw several figure eights without the batter breaking.
Transfer the batters to separate piping bags with small round piping tips (I used Ateco 802 & 803).
Place your macaron template under another piece of parchment paper on a baking sheet and pipe the batter perpendicular to fill in each circle.
Carefully remove the template and tap the baking sheet on the on counter a few times in order to release any air bubbles. It also helps to bang on the bottom of the baking sheet with your hand. Add the white sprinkles, if using.
Let the macarons rest for about 30-45 minutes, or until they are dry and no longer sticky to the touch.
Meanwhile, preheat the oven to 300 degrees F.
Bake the macarons for about 12-14 minutes. Allow to cool completely before peeling them off of the parchment paper.