Preheat oven to 425 degrees F. Melt butter in the microwave in short bursts. Add two tablespoons of the butter to a 12 inch cast iron skillet. Place skillet in oven to preheat. Reserve 2 tablespoons of butter for the batter.
Add the milk, eggs, flour, sugar, salt to a blender and blend on high for 30 seconds until the batter is very smooth. Pulse in the remaining 2 tablespoons of butter very last.
Remove skillet from the oven and quickly pour in the batter. Return to the oven and bake for 15-18 minutes. With a smaller skillet, you might need to bake it longer as your pancake will be thicker.
When pancake is done baking, remove and top with sliced brie cheese and drizzle liberally with honey.