Cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Beat in the eggs one at a time, then stir in the vanilla extract.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Stir in the lemon zest and lemon juice until evenly distributed.
Gently fold in the blueberries.
In a small bowl, cream together the softened cream cheese and sugar until smooth and creamy.
Beat in the egg yolk, then stir in the flour until just combined.
Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
Drop rounded tablespoons of cookie dough onto the prepared baking sheet. Then, drop small dollops of the cheesecake mixture on top of each cookie. Use a toothpick or knife to swirl the cheesecake mixture into the cookie dough.
Bake for 10-12 minutes, or until the edges are golden brown and the centers are set.
Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.
