1. Preheat the oven to 350°F (175°C) and grease a 9×9-inch baking dish.

2. Peel, core, and uniformly slice the apples and place them in a large bowl.

3. Add granulated sugar, brown sugar, and cinnamon to the apples and toss until evenly coated. Let rest for 10 minutes.

4. In a separate bowl, whisk together flour, baking powder, and salt.

5. Stir in milk until a smooth batter forms, then mix in the melted butter.

6. Pour half of the batter into the prepared baking dish and spread evenly.

7. Spoon the apple mixture over the batter, including any juices.

8. Pour the remaining batter over the apples, allowing some of the fruit to peek through.

9. Bake for 40-45 minutes until the top is golden and the filling is bubbly.

10. Remove from the oven and let rest for 15 minutes before serving.

11. Serve warm, optionally with vanilla ice cream, whipped cream, or a drizzle of caramel sauce.