In a food processor pulse flour and salt until well blended.

Add the cubes of cold butter and pulse until pea sized pieces form.

Add the vinegar and 1/3 cup ice water and pulse until a crumbly dough forms. If the crumbles seem too dry, add up to 2 tablespoons more ice water.

Pour the mixture into a medium mixing bowl and gather into a ball of dough.

Wrap the dough in plastic wrap and flatten it into a 1 inch thick round disc. Chill until firm, about 1 hour. While the dough is chilling, make the filling and streusel.

In a medium bowl, whisk together the ¼ cup sugar, ground cinnamon, and all-purpose flour until well combined. Set aside.

In a medium bowl, combine all the streusel ingredients except for the butter. Add the butter, and using your fingers, blend the butter into the dry ingredients until small clumps form. Set aside.

Preheat oven to 400°F.

On a lightly floured surface, roll out the pastry to a rough 12-14 inch circle.

Sprinkle the sugar and cinnamon mixture all over the rolled out crust leaving 2 inches of the edge uncovered.

Arrange sliced peaches on top of sugar mixture.

Using a pastry brush, brush border of crust with egg wash.

Fold the edges of the tart up over the peaches creating a 1½ -2 inch border pressing down gently. Transfer the tart to a large pizza pan covered with parchment paper.

Brush edges of galette with egg wash.

Sprinkle streusel all over the top of the galette.

Bake the tart for 40-45 minutes or until golden brown and the peaches are softened.

Serve the tart warm, cut into slices and topped with vanilla ice cream or whipped cream.