Preheat oven to 350°. Prepare baking sheet with parchment paper or silicone baking mat.
Mix together dry ingredients: flour, baking powder, and salt into a large bowl. Set aside.
In a stand mixer, whip together butter and sugar until light and fluffy.
Add in egg and sour cream. Mix until combined.
Mix in lemon juice, lemon & vanilla extract, and lemon zest.
Add dry mixture in small increments and mix until just combined.
Gently fold in blueberries with a wooden spoon until mixed throughout.
Using a cookie scoop, drop 1 tablespoon of cookie dough onto prepared cookie sheet.
Bake in oven for about 15-17 minutes until edges are golden brown.
Allow to cool on the baking sheet for about 2 minutes and then remove to a cooling rack.