1. Preheat the  oven to 425ºF. Line the 8 inch round cake pan with parchment paper and grease the sides with butter or cooking spray.

2. In a small saucepan cover  1 ½ cup blueberries with ¾ cups of water and bring to a simmer for 3-4 minutes. Remove from heat.  Using a mesh strainer, drain the liquid from the blueberries, reserving the liquid for the blueberry sauce.  Take care to drain as much of the liquid so that the cake is not soggy.  Set aside. 

3. In a medium size bowl whisk together flour and salt.  Using your hands or a pastry cutter, cut in the butter until the flour mixture has a coarse texture. 

4. Whisk in the egg, milk and vanilla extract and stir until smooth. 

5. Add the 1 tablespoon of baking powder. 

6. Pour the cake mixture into the cake pan. 

7. Evenly dot the top of the cake with the cooled blueberries. 

8. In a small bowl, stir the sugar and cinnamon together.  Evenly sprinkle this mixture over the cake. 

9. Put the cake in the oven and immediately turn the temperature down to 375ºF.  Bake for 25- 28 minutes. 

10. Let the cake cool in the pan for 10 minutes.

To Make the Blueberry Sauce:

Return the blueberry juice to the saucepan and heat on medium heat.  Pour in the sugar, lemon juice and cornstarch slurry.  Heat until the sauce begins to thicken, whisking continuously, another 2-3 minutes.