In a large bowl whisk together salt, flour, sugar and baking powder, make a well in the centre and add egg, egg yolk and butter (cubed), mix together (you can also use a food processor, pulse until dough just starts to come together), remove dough to a flat surface and knead gently until the dough come together and is soft, wrap in plastic and refrigerate for 30 minutes.
Pre-heat oven to 350° lightly grease and flour a 10 inch pie pan.
In a small to medium pot combine 1 cup of blueberries, sugar, flour, salt and cinnamon, bring to a boil over medium heat, cook stirring for approximately 2 minutes until thickened, remove from heat and stir in lemon juice and remaining 1/2 cup of blueberries, let cool.
Remove dough from fridge, roll 3/4 of the dough into 1/8 inch thickness to fill pie plate, the remaining dough roll and you can use a small cookie cutter to make cutouts or make strips for the top of the crostata.
Prick bottom of crust with a fork, spread the crust with a thin layer 2-4 tablespoons of Blueberry Jam, top with cooled blueberry filling, top with dough cut outs or strips. Brush the top of the crust (strips or cut outwith a little milk.
Bake for approximately 30 minutes, after 15-20 minutes you may have to cover around the top of pie crust as it tends to brown quickly. Let cool completely before serving. Enjoy!