Step 1: Preheat your oven to 425°F (220°C).
Step 2: Place your oven-safe skillet in the oven while it’s preheating.
Step 3: In a mixing bowl, whisk together the flour, milk, eggs, melted butter, sugar, vanilla extract, and salt until smooth.
Step 4: Carefully remove the hot skillet from the oven and add 1 tablespoon of butter, swirling it around to coat the bottom.
Step 5: Pour the batter into the skillet over the melted butter, then return it to the oven.
Step 6: Bake for 20-25 minutes, or until puffed and golden brown.
Step 7: Serve immediately, topped with your favorite ingredients.