Preheat Oven: Set your oven to 350°F (175°C). Line a baking sheet with parchment paper.

Prepare Cookie Dough: In a large bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the egg and vanilla extract, mixing until combined.

Add Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Form Dough Balls: Using a cookie scoop or tablespoon, form dough balls and place them on the prepared baking sheet, spacing them about 2 inches apart.

Prepare Cheesecake Swirl: In a small bowl, mix the softened cream cheese and blueberry preserves until smooth.

Add Swirl to Cookies: Make a small indentation in the center of each dough ball and spoon a small amount of the cheesecake mixture into each well.

Swirl: Use a toothpick or the tip of a knife to gently swirl the cheesecake mixture into the cookie dough, creating a marbled effect.

Bake: Bake in the preheated oven for 12–15 minutes, or until the edges are lightly golden.

Cool: Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely