1. Heat oven to 425°. In a large bowl, combine strawberries, honey, orange juice, vanilla, and cornstarch. Gently stir to coat. Allow mixture to sit for 15 minutes.
2. Roll out piecrust on a floured surface and reshape, if necessary, into an approximate 12-inch circle. Transfer dough to a parchment-lined baking sheet. Use a slotted spoon to spoon strawberry mixture into the center of the dough, leaving a 2 to 2½-inch border around the edge. Fold edges up and over the sides of the strawberries, all the way around.
3. In a small bowl, whisk together the egg and water until frothy. Brush egg wash over dough with a pastry brush. Sprinkle dough with a light layer of sugar. Scatter butter pieces over top of strawberries.
4. Bake on center rack until crust turns golden brown and strawberry mixture is bubbly, 20–25 minutes. Cool for 20 minutes. Serve with whipped cream.