Preheat oven to 375F° and place one oven rack one place above center and a second rack one place below center. Line two baking sheets with parchment paper. If using just one pan, bake on center rack. Set aside.
In the bowl of a stand mixer (or in a large bowl if using hand-held beaters) mix sugar and butter until creamy, about 5 minutes on medium-low. Add in cream cheese and beat about 10 seconds to incorporate.
1 cup granulated sugar,, ½ cup unsalted butter (1 stick),, 4 oz cream cheese,
Add the lemon juice and lemon zest, mixing just a few seconds. Add the egg and beat another 10 seconds.
Juice of ½ lemon, 1 Tbsp lemon zest, 1 large egg,
In a medium bowl, add flour, cornstarch, baking soda, and salt. Whisk briefly to combine.
2 ½ cups all-purpose flour, 2 tsp corn starch, 1 tsp baking soda, ½ tsp kosher salt
Add the flour mixture to the batter in two additions, mixing just to incorporate. Scrape down the bowl and mix until fully incorporated, about 20 seconds. Using a rubber spatula, gently fold in the blueberries.
2 cups blueberries
Place about ½ cup granulated sugar in a bowl. Scoop batter with large cookie scoop (3 tbsp) if you want 18 cookies, or a medium cookie scoop (2 tbsp) if you want 24 cookies. Roll cookies in sugar, then shake off excess and place about 3 inches apart on parchment-lined baking sheet. The cookie dough is pretty sticky, you might have to really work to get it out of the scoop. This is normal but if you find it too hard to work with, refrigerate for 30 minutes and then continue. Place about 6 cookies on each baking sheet.
Bake for 10-13 minutes for the large scoops, 8-11 for the smaller scoops, switching baking sheets in the oven half way through baking. Bake until the sides and top become just golden. The tops might still be pretty light, but will deepen as they cool.
Repeat for a second batch of the dough.
Leftovers should be refrigerated and are good up to 3 days after baking.