In a mixing bowl, combine 8 ounces of softened cream cheese, 1 cup of powdered sugar, and 1 teaspoon of vanilla extract. Use a hand mixer to beat until creamy and smooth, about 2-3 minutes. Scoop out small portions (about one tablespoon each) and freeze for 30 minutes.

In a separate bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, 1 tablespoon of cornstarch, and 1/2 teaspoon of salt. In another large bowl, cream together 1/2 cup of unsalted butter, 4 ounces of softened cream cheese, 1/2 cup of granulated sugar, and 1/2 cup of brown sugar until light and fluffy, roughly 3-4 minutes. Then, add in 1 large egg, 2 teaspoons of vanilla extract, and the zest of 1 lemon, mixing until well incorporated.

Gradually add the dry ingredient mixture to the wet mixture, mixing gently until just combined. Fold in 1 cup of blueberries gently without breaking the fruit.

Preheat your oven to 350°F (175°C) and prepare baking sheets by lining them with parchment paper. Using a cookie scoop, take about two tablespoons of dough, flatten it slightly, and place a frozen cheesecake filling in the center. Mold more dough around it, sealing the edges.

Arrange the filled cookies on the baking sheets and bake for 11-13 minutes until golden at the edges but soft in the center.

Cool the cookies on the baking sheets for about 5 minutes before transferring to wire racks. Store leftovers in an airtight container at room temperature for up to five days, or freeze for up to three months.