I call this the 'lazy person pie' which is not a bad thing at all! In fact, I prefer a galette because the ratio of crust to filling is more to my liking. Bonus that it's a little earlier to form and shape the crust.
Prepare pie crust. Place the cold butter and flour into a food processor, along with the salt. Pulse the ingredients together for about 2 minutes, until a grainy mixture forms, like wet sand. Add the water and continue to pulse until a dough ball forms, about 30 seconds. Wrap the dough tightly in plastic wrap, then refrigerator for at least 1 hour, or overnight.
Preheat oven to 375°F. For the Filling: Slice the peaches thinly, then place into a large mixing bowl. Add the lemon juice, vanilla, sugar, flour, and spices. Gently toss the peaches in the mixture until they’re well coated. Set aside.
Once the crust dough is chilled, place it on a lightly floured surface. Flour a rolling pin, then roll the dough out into a large circle, about 14-inch in diameter. It doesn't have to be perfect. That is the beauty of a galette. Line a baking sheet with parchment paper, then transfer the dough onto the paper. Transfer the peaches onto the dough, spread them in even layer, leaving about 3 inches of dough along the edges. (Optional: If you want it to look fancy, place the peaches neatly in circles) Gently fold the dough over the fruit.