Pear Ginger Galette With Hazelnut Crust

Combine the ice water and apple cider vinegar. Set aside.
Pulse the hazelnuts in a food processor until they resemble a coarse meal.
In a large mixing bowl, combine the ground hazelnuts, flour, salt, and sugar. Using a fork, pastry blender, or your fingers, cut the butter into the dry ingredients until the mixture is crumbly. You want the pieces of butter to be about the size of peas.
Pour 3 tablespoons of the water and vinegar mixture over the flour and butter mixture and stir to incorporate. If the dough is dry, add more liquid 1 tablespoon at a time just until it comes together when squeezed.
Shape the dough into a disk and wrap in plastic wrap. Chill for at least one hour and up to 3 days.
Peel and core the pears. Slice 1/4 inch thick.
To make the filling, combine pears and all other ingredients excluding the egg and coarse sugar in a large bowl. Set aside.
Roll your down out into a circle, then fold your dough circle into quarters, transfer to a parchment-lined baking sheet, and unfold. Pile the filling onto the center of the crust, leaving a 2 to 3 inch border. Fold the edges of the dough over the mound of filling. Chill the galette in the refrigerator for 30 minutes on a baking tray.
Preheat your oven to 400u0b0 F. Take the galette out of the refrigerator. Brush the dough with the egg wash and sprinkle with sugar. Bake for 35 to 40 minutes, until the crust is golden brown and the pears are soft, but not mushy. Allow to cool at least 30 minutes before slicing.