Add the beer, milk, flour, eggs, sugar, vanilla and butter to a blender. Blend until smooth.
Add the butter to a 9-inch cast iron skillet. Place in the oven until the skillet is very hot and the butter is melted. Swirl the pan to distribute the butter evenly.
Pour the batter in and place in the oven.
Bake for 15-18 minutes or until the center has puffed and the sides curl inward.
Add the heavy cream, powdered sugar, and vanilla in a bowl, beat with a hand mixer until soft peaks form, about 3 minutes.
Add the peaches to a bowl, sprinkle with sugar, toss to coat.
Slice the Dutch Baby into 4 equal pieces, top with peaches and whipped cream.
Notes
*for a stronger beer flavor replace the 1 teaspoon of vanilla with 1 to 2 tablespoons of beer.