How to Make It
Preheat oven to 450°. Heat a 10-inch cast-iron skillet over medium-high heat 5 minutes. Toss together apple slices and sugar in a small bowl. Melt 1 Tbsp. butter in skillet. Add apples, and sauté 3 to 5 minutes or until tender. Remove apples from skillet, and wipe skillet clean.
Whisk together eggs and milk in a medium bowl. Whisk in flour and next 3 ingredients. Melt remaining 2 Tbsp. butter in skillet over medium-high heat. Immediately pour egg mixture into hot skillet, and top with cooked apples.
Bake at 450° for about 20 minutes or until pancake is golden and puffed.
Meanwhile, stir together sour cream and brown sugar in a small microwave-safe bowl. Microwave at HIGH 45 seconds. Whisk until sugar dissolves. Stir in apple cider, 1 Tbsp. at a time, until desired consistency is reached. Serve with hot pancake.