Ingredients
4 tablespoons unsalted butter, room temperature
1 Granny Smith apple, peeled, cored, and chopped into 1/2" pieces (1 1/2 cups)
3 tablespoons sugar
1 teaspoon ground cinnamon
1/2 cup unbleached all-purpose flour
1/2 teaspoon kosher salt
3 large eggs, room temperature
3/4 cup whole milk, room temperature
1/2 teaspoon pure vanilla extract
Greek yogurt or skyr, fresh fruit, and honey for serving
Preparation
Over medium heat, melt 1 tablespoon butter in a medium cast-iron skillet (10 inches, measured across top). Stir in apple, 1 tablespoon sugar, and cinnamon, and cook until crisp-tender, about 2 minutes; transfer to a plate and wipe skillet clean.
Preheat oven to 425°F and place now-clean skillet on center rack. In a bowl, whisk together flour, remaining 2 tablespoons sugar, and salt.
Purée eggs in a blender until pale and frothy, about 1 minute. Add flour mixture, milk, and vanilla. Purée until smooth, about 30 seconds (the batter will be thin).
Add remaining 3 tablespoons butter to skillet in oven. When it melts and sizzles, pull out the rack and quickly pour batter into center of skillet. Sprinkle apple mixture evenly over batter.
Bake until pancake is puffed, golden brown in places, and crisp along the edges, 18 to 22 minutes. Slice into wedges and serve immediately with yogurt, fruit, and syrup.
