Preheat oven to 425°. On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim crust to 1/2 in. beyond rim of plate; flute edge. Arrange bread in bottom of pie crust. In a large bowl, whisk eggs, milk, sugar and vanilla; pour over bread. Sprinkle with nutmeg and dot with butter. Bake 10 minutes. Reduce oven setting to 350°., Bake until a knife inserted in the center comes out clean, 45-50 minutes longer. Cover edge loosely with foil during the last 15 minutes if needed to prevent overbrowning. Remove foil. Cool on a wire rack 1 hour. Refrigerate for at least 3 hours before serving.