Add the berries, sugar, lemon juice, zest, salt and cornstarch to a medium saucepan. Bring to a boil over medium heat, stirring often for 5-7 minutes or until jam thickens. Stir in vanilla then pour jam into a bowl. Place bowl in the fridge to cool. Jam will continue to thicken as it cools. 

Chop butter into cubes and place in the fridge while you assemble the rest of the ingredients.

Fill a small bowl with some cold water and an ice cube. Stir the ice cube around a bit and set bowl aside.

In a food processor, pulse together the flour, sugar, and salt. Add the cubed butter and pulse until the dough forms pea sized balls. Add ice water a tablespoon at a time while continuing to pulse mixture until it is just combined. 

Turn dough out onto a floured surface and knead a couple of times to help the dough come together a little. Gently flatten the dough into a disk about one inch thick and cover it with plastic wrap. Chill the dough in the fridge for 30 minutes to an hour.

When ready to assemble pie cookies, remove the dough from the fridge and let it stand at room temperature for 15 minutes. Line a baking sheet with parchment paper, generously flour your counter, and prepare your egg wash by whisking together the egg and milk. Set aside. 

Roll the dough out on your floured counter to about 1/8" thickness. 

Lightly flour your 3" cookie cutter or biscuit cutter and cut out circles. Place the circles on your baking sheets. Scraps can be rolled out a second time. 

Spoon a rounded teaspoon of  jam onto the crust and spread it with the back of your spoon or an offset spatula, leaving a 1/4 inch border.  Carefully place a top circle over the bottom crust. Gently press the edges of the dough with your finger tips to seal the top and bottom crusts together. Use a fork to crimp all the edges. (Lightly dip fork in flour if needed to prevent sticking). Use a fork or a toothpick to poke a few holes in the dough or use a knife to cut an X in the middle of each pie. Place the tray of pie cookies in the fridge for 15 minutes. Preheat oven to 375 F.

Remove pie cookies from fridge and brush the tops allover with the egg wash. Sprinkle with granulated sugar and or a little turbinado sugar. Bake for 17-24 minutes or until the crust is golden. Remove from heat and transfer to a rack to cool. Once cooled, serve with a drizzle of icing or enjoy as is! 

Stir together the powdered sugar, heavy cream, milk, and vanilla. Drizzle over the pie cookies!