How to Make Hazelnut Macaron Shells

• In the mixing bowl of a stand mixer add room-temperature egg whites and start whisking on low speed. Start adding sugar one tablespoon at a time.  Increase speed to medium-high and whip until stiff picks. This will take 10-15 minutes. 
• In the mixing bowl, sift hazelnut flour.
• Using a kitchen scale, measure sifted hazelnut flour and powdered sugar.
• Sift together sifted before hazelnut flour and powdered sugar.
• Add dry ingredients to the French meringue and start folding the butter. When macaronage drips down from the spatula “like lava”, transfer it into a pastry bag with a round tip.
• Pipe macaron shells on the baking mat. 
• Top baking sheet pan with pipped macaron shells a few times. Let shells rest on the countertop until no batter sticks to your finger when you touch it. 
• Bake macaron shells in the preheated oven to 275^o F (134^o C) for 12-14 minutes. If you have a "convection bake" setting in the oven then use it. Oven temperature and baking time may vary, depending on your oven. 
• Remove baked macaron shells from the oven and let it cool on the baking mat with a baking sheet pan. When shells are cooled completely remove from baking mat and pair them with similar size.