2-3Tbspgranulated sugar for sprinklingturbinado preferred but not required
Cut butter into small pieces and set aside.
In food processor pulse together flour, cornstarch, sugar and salt.
Add butter and pulse until mixture forms fine crumbs
Add water, about 1 Tbsp at a time until dough begins to cling together (you may need an additional Tbsp or 2 of water).
Pour crumbs into parchment paper and press together using palm of hand.
Gather into a ball, wrap tightly with clear-wrap and refrigerate for at least one hour.
While the dough is chilling, combine raspberries and chocolate chips.
Sprinkle vanilla extract over raspberries/chocolate chips and stir well.
In small bowl, combine granulated sugar and cornstarch.
Pour over raspberry/chocolate mixture and stir well.
Cover and transfer to fridge and allow mixture to sit while dough finishes chilling.
Once dough has finished chilling, remove from fridge and allow to soften on countertop for 10 minutes.
Preheat oven to 400F,
Break dough into 7 equal pieces, place on lightly floured surface and roll each piece out into approximately 4.5"-5" diameter circle (does not have to be an exact circle, part of the beauty of galettes is their rustic appearance) and transfer to parchment-paper lined cookie sheet.
Remove the filling from the refrigerator and drain as much excess liquid as possible from it.
Equally portion filling out amongst all galettes, making a small pile in the center leaving about 1" of space around the edges.
Gently fold edges partially over the filling.
In small bowl, whisk together egg and milk or cream.
Using a pastry brush, brush mixture over galette crust.
Sprinkle galettes(crust and filling) generously with sugar (about 1 tsp per galette)
Bake in oven on 400F for 30 minutes or until crusts are golden brown.