Preheat oven to 425°
Place coconut oil in a 9-inch cast-iron skillet and heat it on the stove on low/medium heat for a few minutes. Let the oil melt and the skillet heat up in the oven for about 10 minutes.
In a blender, add all the ingredients EXCEPT the blueberries.
Remove the cast iron and pour the batter evenly into the pan. Then top with the blueberries.
Place it in the oven and bake for about 18-23 minutes. My oven cooks fast so mine was done in about 18 minutes. If yours starts to puff up a lot, remove it.
Allow your dutch baby to cool for about 5 minutes and top with powdered sugar. Serve with syrup and enjoy.