Place the butter in a 10-inch oven-safe skillet and place the skillet in the oven until butter is melted. Remove the pan from the oven and add the apples. Return to the oven for 5 minutes.
In medium bowl, whisk together the eggs, milk, flour, salt and brown sugar.
Remove the pan from the oven and pour the mixture over the apples. Return the pan to the oven for 15 to 18 minutes, or until puffy.
Mix the sugar and cinnamon together and sprinkle over the hot pancake. Cut into slices, and serve immediately.