Prepare the Cream Cheese Filling: In a medium bowl, blend 8 oz of softened cream cheese, 3 tablespoons of granulated sugar, and 1 teaspoon of vanilla extract using an electric mixer until fluffy and smooth. Scoop into small balls and freeze for 30 minutes.

Make the Blueberry Jam: In a saucepan over medium heat, combine 2 cups of fresh blueberries and 1/2 cup of granulated sugar. Cook for about 40 minutes until thickened. Cool before refrigeration.

Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper. In a large bowl, whisk together 2 cups of flour, 1 teaspoon of baking powder, 1/2 teaspoon of baking soda, and 1/4 teaspoon of salt.

In another bowl, cream together 1 cup of softened unsalted butter and 1 cup of granulated sugar until light and fluffy, about 5 minutes.

Incorporate 1 room temperature egg and 2 tablespoons of lemon zest into the butter-sugar mixture. Mix until well combined.

Gradually add dry ingredients to the wet mixture, stirring gently until just incorporated. Gently fold in 1/2 cup of blueberry jam until only a few swirls are visible.

Form Cookies: Scoop a portion of dough, flatten it, place a frozen cheesecake ball in center, wrap dough around, and roll into a ball. Roll in granulated sugar and place on baking sheets.

Bake for 11 to 12 minutes until lightly golden around edges. Cool on the baking sheet briefly before transferring to a wire rack.