Preheat oven to 400. Start with the filling - melt the butter in a 10-inch ovenproof frying pan over medium-high heat. Add the apples, sugar, and cinnamon and saute, stirring constantly, until the apples begin to soften and brown lightly, 3-5 minutes. Remove from the heat.
To make the pancake, in a bowl, using an electric mixer set on medium speed, beat the eggs. Add all of the other ingredients and beat until just smooth. Immediately pour over the apples in the hot pan, and place in oven. Bake until nicely puffed and golden brown, ~25 minutes. Lightly dust with powdered sugar, serve.