Preheat oven to 400°F and line a rimmed baking sheet with parchment paper.
Unroll one pie crust and press it to cover the center of the baking sheet.
Toss strawberries with granulated sugar, cornstarch, lemon juice, and vanilla, then spread over the crust leaving a 1-inch border.
Unroll second crust and lay over filling, pressing edges together with a fork to seal; cut a few vents on top.
Brush entire top crust with egg wash.
Bake 25-30 minutes until crust is deep golden and filling is bubbling.
Cool 20 minutes, then whisk powdered sugar and milk together and drizzle over the top.