Preheat oven to 350 degrees F.
Gather cookie dough ingredients and make blueberry powder by blending freeze-dried blueberries in a spice grinder, blender, or food processor. Set powder aside while you make the dough.
In the bowl of a stand mixer fitted with paddle attachment or with a hand mixer, cream butter and sugars until fluffy before adding egg, vanilla, and lemon zest. Blend again until combined and fluffy.
Add dry ingredients and mix until well combined and a dough forms.
Divide dough in half. Add blueberry powder to one half and mix well to fully combine.
Portion both doughs out into 1 tablespoon balls.
Place two balls together, fold them over each other once or twice depending on how swirled you want them and then roll into a ball.
Roll in sugar and place onto a parchment lined tray about 2 inches apart, flattening the tops very slightly.
Bake in preheated oven for 8 minutes. Repeat until all dough balls have been baked.
Let cookies cool on tray for a few minutes before transferring to racks to cool completely before storing.
