Preheat oven to 425 degrees F.
Place butter in an oven-proof 8-9" skillet and place in the oven.
Meanwhile, add milk, eggs, vanilla, flour, sugar, and salt to a blender and blend until well combined. You might have to scrape down the edges once or twice.
Remove skillet from the oven and pour batter over the melted butter.
Return skillet to the oven and bake 25-30 minutes, until pancake is puffed and the top is set. It was still slightly jiggly but the top was not sticky or wet.
Remove from the oven and let sit for 5 minutes.
Serve topped with maple syrup, powdered sugar, and/or berries.
Slice and enjoy!