Line a baking sheet with a silicone baking mat or parchment paper.
Use a food processor to pulse the powdered sugar, almond flour until fully combined and rid of lumps. Sift the combined ingredients into a large bowl. If you do not have a food processor you can just sift the ingredients together. Set aside
In a medium bowl, beat the egg whites on low speed until they start to get foamy. Slowly add the granulated sugar and increase the speed. Beat the mixture until stiff peaks form.
Add the meringue into the dry ingredients and use a silicone spatula to gently fold the two together. Add in the food coloring and whisk to combine. The batter should be fully combined and not streaky. The batter is ready when it falls off of the spatula in a thick ribbon. It should not be too runny.
Transfer the mixture to a piping bag fitted with a piping tip. Pipe about 1-inch disks onto the prepared baking sheet.
Firmly tap the baking sheet 5 or 6 times on the counter to bring any air bubbles to the surface. Use a toothpick to pop any remaining bubbles.
Let the macarons rest for at least 1 hour. You should be able to gently run your finger over the surface of the macarons without any getting on your finger.
Preheat your oven to 325°. Place the baking sheet on the center rack of the oven and bake for 15 minutes, rotate the pan every 5 minutes to ensure even baking and coloring.
Remove the macarons from the oven and allow to cool completely on the baking sheet.
Gently peel each cooled macaron off of the mat and match up with a similarly sized cookie.