Add a 10-inch cast iron skillet to an oven and preheat to 400°F.
In the meantime, add the milk, eggs, melted butter, flour, salt, and vanilla to a blender and blend on high for 20 to 30 seconds or until very smooth. Set it aside.
Remove the skillet once it has been preheated and add in the 2 tablespoons of butter and heat until it is melted.
Immediately pour in the batter from the blender and bake at 400°F for 20 minutes or until browned, firm, and the batter has crawled up the sides of the pan.
Remove the Dutch baby from the oven and garnish with fresh berries, whipped cream, and powdered sugar.