In a large bowl, whisk together the eggs, milk, flour, and salt. Let rest in the refrigerator for 10 minutes.
Melt butter over medium-high heat in a 12-inch cast-iron or nonstick ovenproof skillet. When the foaming subsides, add apples and half of the sugar mixture. Once apples begin to soften, add batter and the rest of the sugar mixture. Immediately place into the preheated oven and bake until the pancake puffs and browns.
Remove from oven and sprinkle with powdered sugar. Slice and serve with warm maple syrup.