1tablespoonfresh lemon zest, from 1-2 medium lemons
1large egg
1teaspoonvanilla extract
2 ⅓cups(331g)all-purpose flour
½cup(113g)sour cream
2cups(340g)fresh blueberries
2tablespoonssparkling or coarse, raw sugar
Glaze:
1 ¼cups(143g)powdered sugar
1teaspoonfresh lemon zest
2-3tablespoonsfresh lemon juice
Instructions
Preheat the oven to 375 degrees F. Line two baking sheets with parchment paper. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment (or in a large bowl using an electric hand mixer), combine the butter, granulated sugar, brown sugar, baking powder, salt, and lemon zest. Mix until light and fluffy, 2-3 minutes, scraping down the sides of the bowl as needed. Add the egg and vanilla and mix well.
With the mixer on low speed add 1/3 of the flour. Mix until mostly combined (a few dry streaks are ok). Mix in half of the sour cream followed by another 1/3 of the flour. Mix in the last half of the sour cream and then the last 1/3 of flour. Mix until just combined and no dry streaks remain.
Add the blueberries and mix gently (I find it's easiest to dig in with my hands and gently fold the blueberries into the batter).
Scoop the batter in mounds (about 2-3 tablespoons in size or up to 1/4 cup of batter for each cookie for large cookies) and place several inches apart on the prepared baking sheets. Sprinkle the tops of the cookie dough with coarse sugar.
Bake the cookies for 12-15 minutes until the top springs back lightly to the touch and isn't doughy in the center. Let cool on the pans for several minutes before transferring to a cooling rack to cool completely.
For the glaze, in a small bowl whisk together the powdered sugar, lemon zest and lemon juice until smooth - the consistency should be thick but drizzle-able. Add more lemon juice a teaspoon at a time to thin (or whisk in a bit more powdered sugar for a thicker glaze). Drizzle the tops of the cooled cookies with the glaze.