In a small bowl, mix together the coconut sugar and the spices. (If using maple syrup, skip this step and add the maple syrup and spices to the skillet in the next step.)
Melt the butter in a large cast iron skillet. Once the butter is melting, add the apples and sprinkle with the coconut sugar spice mixture you already mixed together. Stir and cook gently.
While the apples are cooking, whisk together the eggs, milk, salt, vanilla, and flour in a medium bowl. Whisk until the mixture is smooth.
Once the apples are beginning to soften, remove skillet from the heat and allow the pan to cool down slightly. Pour the batter over the apples.
Put the skillet in the preheated oven and bake for 20-30 minutes, until the pancake is puffed and golden. Serve with maple syrup or powdered sugar.
Notes
If you want this recipe to be gluten free, use almond flour in place of the spelt flour. For a dairy free version, use almond or other nut milk in place of regular milk.