Preheat the oven to 425°F. Place a 10-inch cast-iron skillet inside it and let the pan preheat for at least 5 minutes.

In a blender, place the eggs, flour, milk, sugar, salt, and nutmeg. Blend until smooth.

Carefully remove the hot skillet from the oven and add the butter. Swirl to coat the bottom and sides of the pan, then pour in the batter. Return the pan to the oven and bake for 13 to 16 minutes, or until the edges are puffed and golden brown and the center is set.

Remove from the oven and use a spatula to remove the Dutch baby from the pan. Transfer to a serving dish and dust with powdered sugar. Serve with fresh berries.