Creating the Apple Cinnamon German Pancake is a straightforward process if you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 425°F (220°C).
2. Prepare the Baking Dish: In a 10-inch cast-iron skillet or oven-safe dish, melt the butter in the oven while it preheats.
3. Mix the Batter: In a mixing bowl, whisk together the eggs, milk, flour, granulated sugar, vanilla extract, salt, and ground cinnamon until smooth.
4. Prepare the Apples: In a separate bowl, toss the sliced apples with a little cinnamon and sugar if desired.
5. Add Apples to the Skillet: Once the butter has melted, carefully arrange the sliced apples evenly in the skillet.
6. Pour the Batter: Pour the batter over the apples, ensuring they are well covered.
7. Bake: Place the skillet in the preheated oven and bake for 20 minutes or until the pancake is puffed and golden brown.
8. Serve: Remove from the oven and let it cool slightly before dusting with powdered sugar.
9. Slice and Enjoy: Cut into wedges and serve warm.

These instructions will guide you in creating this incredible pancake with ease.