Preheat oven to 375 F. Combine sugar and zest into one small bowl. Using your fingers massage the zest into the sugar to help extract the oils. Set aside.
In a stand mixer fitted with a paddle attachment, add butter, sugar, fresh lemon juice and salt. Mix on medium high until creamed – about 2 to 3 minutes or until light and fluffy. Scrape down bowl as needed.
Add egg and mix on medium low until fully incorporated. Scrape down bowl as needed with rubber spatula.
In a blender or food processor, add freeze dried blueberries and grind down for just a few seconds.
Place fine mesh strainer over stand mixer bowl and sift blueberry powder in. Discard remaining seeds. Mix on medium low until blueberries are fully mixed in. Scrape down bowl as needed.
In a separate bowl, add flour and baking powder and sift well. Add to wet ingredients.
Mix dry ingredients on low until about half the flour has been absorbed. Then turn on one notch higher and mix until well combined.
Lay down large piece of parchment, and flour lightly. Place dough on top and flatten slightly, and lightly flour top. Add piece of parchment on top and use rolling pin to roll to desired thickness.
Cut shapes with cookie cutters and place on cookie sheet at least 1" apart. Re-roll as needed, lightly flouring bottom and top.
Bake for 9 minutes, or until you see very light browning along bottom edges.
Remove from oven and place on wire rack. Allow to completely cool before enjoying or decorating.