Grape Dutch Baby
  1. Heat oven to 450 degrees.
  2. Put large (10-inch) cast-iron or ovenproof skillet in oven.
  3. With electric mixer on high speed in a mixing bowl, beat eggs until frothy then beat in flour, milk, vanilla, and salt; beat until smooth, about 1 minute (batter will be thin).
  4. Remove skillet from oven and add 2 tablespoons butter, swirling to cover pan. Pour in batter and return to oven. Bake until puffed and golden brown, 14–19 minutes.
  5. While pancake is baking, in another skillet over high heat, melt remaining butter and add grapes, brown sugar, and cinnamon, if desired.
  6. Cook until grapes are heated through and sugar has melted. Spoon grapes over pancake, sprinkle with confectioners’ sugar, and serve.