1. Line a small baking sheet or plate with parchment paper for the cheesecake filling and set it aside.

2. In a medium bowl, beat the softened cream cheese with 0.25 cup granulated sugar until smooth and creamy with no lumps.

3. Add the vanilla extract and egg yolk to the cream cheese mixture and mix until fully combined and silky.

4. Drop teaspoon or small tablespoon sized dollops of the cheesecake mixture onto the prepared parchment lined tray.

5. Place the tray with cheesecake dollops into the freezer for 30 to 45 minutes, or until the scoops are firm enough to handle.

6. While the cheesecake filling chills, preheat the oven to 350°F (175°C) and line two large baking sheets with parchment paper.

7. In a large mixing bowl, beat the softened unsalted butter, brown sugar, and 0.25 cup granulated sugar together until light and fluffy, about 2 to 3 minutes.

8. Add the whole egg, egg yolk, and vanilla extract to the butter mixture and beat until the mixture looks smooth and glossy, scraping down the sides of the bowl as needed.

9. In a separate bowl, whisk together the all purpose flour, cornstarch, baking soda, and fine sea salt until well combined.

10. Add the dry ingredients to the wet ingredients and mix on low speed just until the flour disappears and a thick dough forms.

11. Use a spatula to fold in the semi sweet chocolate chips and chocolate chunks, making sure they are evenly distributed throughout the dough.

12. Scoop a generous portion of dough, about 2 to 3 tablespoons, and flatten it into a thick disc in the palm of your hand.

13. Place one frozen cheesecake dollop in the center of the dough disc and carefully wrap the dough around it, pinching to seal all seams.

14. Roll the stuffed dough into a smooth ball and place it on a parchment lined baking sheet, leaving space between each cookie.

15. Repeat with the remaining dough and cheesecake filling, adding a few extra chocolate chips or chunks on top of each ball if desired.

16. Chill the stuffed cookie dough balls in the refrigerator for 30 minutes, or in the freezer for about 15 minutes, to help them hold their shape.

17. Bake the cookies one sheet at a time for 11 to 14 minutes, or until the edges are lightly golden and the tops look just set but still soft in the center.

18. Remove the baking sheet from the oven and let the cookies cool on the pan for 10 minutes so the cheesecake centers can finish setting.

19. Transfer the cookies carefully to a wire rack to cool completely, or enjoy them slightly warm for the gooiest cheesecake centers.

20. Store any leftover cookies in an airtight container in the refrigerator for 4 to 5 days, warming them briefly before serving for the best texture.