Preheat the oven to 425 degrees F. Put a 10-inch cast iron skillet into the oven and heat for at least 8 minutes.
In a high-powered blender combine eggs, flour, milk, white sugar, salt and vanilla. Blend until the batter is completely smooth.
Remove the skillet from the oven and place it on top of the stove. Add the butter and swirl in the pan to melt, making sure to coat the bottom and sides of the pan.
Pour the batter on top of the butter, tilting the pan if needed to make sure the batter is evenly distributed. Place the skillet in the oven at 425 degrees F.
Bake until the Dutch baby is puffed, lightly browned across the top and darker brown on the edges and sides, about 15-20 minutes.
Immediately sprinkle powdered sugar and cut into wedges to serve. We recommend serving with fresh berries and syrup.
