This can easily be made dairy free by substituting your favorite butter substitute(either dairy free margarine or substitute just 1 tbsp coconut oil for the 2 tbsp butter) and your favorite dairy free milk.
Please note the baking time in my recipe. I wrote 20-30 minutes because different pan sizes can be used, but the baking time will be different. I use a 10" cast iron skillet and in my oven it takes just about 23-24 minutes, but a smaller pan will take longer to cook since the batter is thicker. The dutch baby is done when it is fully puffed up, dark to golden brown on the edges and completely set in the middle.