1. Preheat oven to 350°F.

2. Lightly coat an 8-inch square pan with nonstick spray, then line with parchment paper, leaving overhang on the sides.

3. Lightly spray the parchment paper.

4. In a medium bowl, gently mix raspberries, cornstarch, lemon juice, and sugar until combined, then set aside.

5. In another bowl, whisk together flour, sugar, baking powder, salt, and cinnamon.

6. Work the cold cubed butter into the dry mixture with your hands until it resembles coarse crumbs.

7. Add the egg yolk, water, and vanilla extract, then stir with a fork until the mixture begins to form a dough.

8. Press about two-thirds of the dough firmly and evenly into the bottom of the prepared pan.

9. Spread the raspberry mixture over the crust.

10. Sprinkle chocolate chips evenly over the raspberries.

11. Crumble the remaining dough evenly over the top.

12. Bake for 40 to 50 minutes, until the raspberries are bubbling and the crumble is golden brown.

13. Cool completely in the pan for 2 to 3 hours.

14. Lift the bars out using the parchment overhang, slice, and serve.