Stir the flour, salt and sugar together in a large bowl. Add the butter pieces and coat with the flour mixture using a bench scraper or spatula. With a pastry blender, cut the butter into the flour mixture, working quickly until mostly pea-size pieces of butter remain (a few larger pieces are okay; be careful not to over blend).
Combine the water, ice and cider vinegar in a large measuring cup or small bowl. Sprinkle 2 tablespoons of the mixture over the dry ingredients, and mix and cut it in with a bench scraper or spatula until it is fully incorporated. Add more of the ice water mixture, 1 to 2 tablespoons at a time, using the bench scraper or your hands (or both) to mix until the dough comes together in a ball, with some dry bits remaining. Squeeze and pinch with your fingertips to bring all the dough together, sprinkling dry bits with more small drops of the ice water mixture, if necessary, to combine. Shape the dough into a flat disc, wrap in plastic, and refrigerate for at least 1 hour, preferably overnight, to give the crust time to mellow.
Wrapped tightly, the dough can be refrigerated for 3 days or frozen for 1 month. This recipe makes two galettes, so I always half of the dough in the freezer so I can easily make one later.
For the brown sugar peach filling:
Preheat oven to 400°F.
Place sliced peaches in a large bowl. Sprinkle C&H® Dark Brown Sugar, flour, lemon juice, vanilla and salt. Toss with a fork until peaches are evenly coated.
Remove one chilled dough round from fridge and roll out to 1/8-inch thick on a floured surface. Transfer to a parchment paper-lined baking sheet.
Arrange peach slices in a circle, leaving a two-inch border.
Fold the uncovered dough over the peaches in an overlapping fashion, leaving some of the center exposed. The nice thing about galettes is that it doesn’t have to be perfect!
Refrigerate for 20 minutes until the galette firms up.