In a large bowl, whisk together flour, granulated sugar (for dough), and salt (for dough). Add the cold, cubed butter. Using a pastry blender, your fingertips, or a food processor, cut the butter into the dry ingredients until it resembles coarse meal with some pea-sized pieces of butter remaining.

Gradually add the ice water, 1 tablespoon at a time, mixing gently until the dough just comes together. Be careful not to overmix. Form the dough into a disk, wrap it tightly in plastic wrap, and refrigerate for at least 30 minutes (or up to 2 days).

In a medium bowl, combine cranberries, granulated sugar (for filling), cornstarch, orange zest, vanilla extract, and a pinch of salt (for filling). Stir gently to coat the cranberries evenly. Set aside while you roll out the dough.

Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.

On a lightly floured surface, roll out the chilled dough into a rough 12-14 inch circle (it doesn't have to be perfect, as it's a rustic galette). Carefully transfer the rolled dough to the prepared baking sheet.

If using, sprinkle the almond meal evenly over the center of the dough, leaving a 1 1/2 to 2-inch border around the edge.

Spoon the cranberry filling onto the center of the dough, over the almond meal (if used), leaving the border clear.

Gently fold the edges of the dough over the filling, pleating as you go, to create a rustic crust around the cranberries. The center of the filling will remain exposed.

In a small bowl, whisk together the beaten egg and water to make an egg wash. Brush the egg wash over the folded dough crust. Sprinkle the turbinado sugar generously over the egg-washed crust.

Bake for 35-45 minutes, or until the crust is golden brown and the cranberry filling is bubbly and tender. If the crust starts to brown too quickly, you can loosely cover it with foil.

Remove from oven and let the galette cool on the baking sheet for at least 15-20 minutes before slicing and serving. This allows the filling to set.