Preheat your oven to 400°F (200°C). Place a 10-inch cast iron skillet inside while the oven heats. This will ensure your skillet is hot enough to create that lovely puff.
In a mixing bowl, combine the eggs, milk, flour, sugar, vanilla, and salt. Blend until the mixture is smooth, with no lumps. You can use a whisk or an electric mixer for this.
Let the batter rest for about 10 minutes. This resting time allows the flour to absorb the liquid, resulting in a fluffier texture.
Once the oven is preheated, carefully remove the hot skillet with oven mitts. Add butter to the skillet and swirl it around to coat the bottom and sides. It should melt quickly, creating a sizzling sound.
Immediately pour the prepared batter into the hot skillet. Be careful—this can be a bit splattery. The batter should sizzle as it hits the hot skillet.
Return the skillet to the oven and bake for 20 minutes. During this time, resist the urge to open the oven door; doing so can cause the Dutch Baby to collapse.
When the baking time is up, check that the Dutch Baby is puffed and golden brown. It should be slightly crispy on the edges.
Carefully remove the skillet from the oven and let it cool for just a minute. Dust generously with confectioners’ sugar and get ready to serve!
For an added touch, serve immediately with fresh lemon wedges on the side. The acidity of the lemon complements the sweetness of the Dutch Baby beautifully.