Preheat oven to 350F.
In a bowl or blender, combine your milk, eggs, vanilla, salt, flour and half of the sugar, whisking or blending until ingredients are evenly mixed together. The batter will be quite runny, similar to a thin pancake batter.
Pour half of the batter into a baking dish, or in my case, a 9-10 inch cast-iron pan lined with parchment paper (as I had no baking dishes).
Place the first half in the oven, baking for about 10 minutes.
In a bowl, mix the blueberries with the rest of the sugar until evenly coated.
After 10 minutes is up, remove the clafoutis, evenly spreading the blueberries on the batter and pouring the rest of the batter over top of them.
Place the clafoutis back in the oven, baking for about 40-50 minutes until the top is browned and you can insert a toothpick and it comes out clean.
Once the clafoutis has cooled to room temperature, lightly sprinkle with powdered sugar and serve with whipped cream, ice cream, or on its own!