Step 1

Preheat oven to 375°F. Position oven rack in bottom third of oven. Unroll 1 piecrust on a lightly floured surface, and lightly brush top of piecrust with 2 tablespoons water. Unroll remaining piecrust, and place on top of crust on lightly floured surface. Roll stacked piecrusts into a 13-inch circle. Transfer to a large rimmed baking sheet lined with parchment paper. Refrigerate, uncovered, until ready to use, up to 15 minutes.

Step 2

Whisk together brown sugar, cornstarch, lemon zest, salt, and ground ginger in a large bowl until combined. Gently stir in peaches, vanilla, and lemon juice until peaches are fully coated. Arrange peach slices in an even layer in concentric circles on piecrust, starting from outside and leaving a 2-inch border around edges. Drizzle peaches with any remaining juices from bowl. Fold edges of piecrust over fruit, pleating as needed. Brush crust with cream; sprinkle crust and fruit with sparkling sugar.

Step 3

Bake in bottom third of preheated oven until filling is bubbling and crust is golden brown, about 50 minutes. Transfer baking sheet to a wire rack; let galette cool to room temperature, about 30 minutes. Serve with ice cream or whipped cream.