In a bowl, combine cold cream cheese, 3 tablespoons sugar, and ½ teaspoon vanilla. Whip on medium-high until smooth and fluffy, about 3–4 minutes. Portion into small scoops or tablespoons, place on a parchment-lined tray, and freeze at least 1 hour.

In a small saucepan, combine 12 oz fresh blueberries and ¼ cup sugar. Cook over medium heat, stirring occasionally, and gently mash berries as they soften. Simmer about 30–40 minutes until thickened. Cool to room temperature, then chill in the fridge.

Whisk together 2 ¾ cups flour, ½ tsp baking powder, ½ tsp baking soda, and ½ tsp salt in a medium bowl.

Combine 1 cup granulated sugar and 2 tablespoons lemon zest. Rub the zest into the sugar with fingertips until fragrant.

In a mixing bowl, cream the lemon-zested sugar with 1 cup softened unsalted butter until light and fluffy, about 2–3 minutes.

Beat in the egg and 2 teaspoons vanilla until the mixture is pale and well combined.

Gradually add the dry ingredients to the butter mixture, mixing until just combined. The dough should be soft but not sticky.

Divide dough into 1½–2 tablespoon portions. Flatten one portion, place a teaspoon of chilled blueberry jam and one frozen scoop of cheesecake filling in the center, then top with another flattened dough portion. Pinch edges to seal well and roll into a smooth ball.

Preheat oven to 350°F (175°C). Roll each dough ball in ¼ cup granulated sugar to coat. Place on a parchment-lined baking sheet 2 inches apart. Bake for 11–12 minutes until edges are set and lightly golden but centers remain soft. Cool on the sheet for 10 minutes.

Transfer to a wire rack to cool completely. The frozen cheesecake center stays creamy once the cookie cools.