Entirely Elizabeth

In a small bowl, rub together the granulated sugar and lemon zest until well incorporated. Set aside.

In a large bowl, whisk together all-purpose flour, baking powder, cornstarch, and salt. Set aside.

Using a hand mixer or stand mixer fitted with a paddle attachment, cream together melted unsalted butter, lemon sugar (from step 1), and brown sugar. This takes 2 to 3 minutes and the mixture should become pale in color.

Add lemon juice, sour cream, and egg. Combine until the mixture is smooth and fully incorporated.

Add the dry flour mixture and combine. It will be a smooth but slightly sticky dough.

Cover the surface of the lemon cookie dough with plastic wrap and refrigerate for  30 minutes to 1 day.

Preheat oven 350 °F and prepare 2 large cookie sheets with either parchment paper or silicone baking mats.

Scoop 2 to 3 tablespoons of lemon cookie dough (use a large cookie scoop for even sizes) and roll into a smooth ball. Place on prepared baking sheet and continue until all the cookie dough is gone.

With a fork press the lemon cookie dough balls down to a ½ inch thick making a crisscross pattern. If the fork sticks dip it in all-purpose flour to prevent it.

Scoop 1 to 2 teaspoons of seedless blueberry jam and place it in the center of the cookie. Spread the jam close to the edge of the cookie without letting it spill over.

Bake in the oven for 9 to 11 minutes or until the bottom, lower outer edges of the cookies are slightly browned.

Remove cookies from the oven and allow them to cool on the baking sheet for 10 minutes prior to transferring to a cooling rack. Allow them to cool completely before moving on.

In a small bowl, mix together powdered sugar and lemon juice until you have a thick glaze.

Drizzle the lemon glaze over top the completely cooled lemon blueberry cookies. Top with more lemon zest.

Allow the lemon glaze to dry and harden prior to serving.