Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish with butter or nonstick spray.

In a large bowl, toss the sliced apples with ½ cup sugar, cinnamon, and 3 tablespoons flour. Set aside to macerate while you prepare the batter.

Pour the melted butter into the bottom of the baking dish.

In another bowl, whisk together 1 cup flour, 3 tablespoons sugar, baking powder, and salt. Stir in the milk and vanilla extract until smooth to form the cobbler batter.

Gently pour the batter over the melted butter—do not stir.

Use a spoon to drop the apple mixture evenly over the batter.

Bake for 30 minutes, or until the top is golden brown and the apples are tender when pierced with a fork.

Let cool for 10 minutes before serving. Top with vanilla ice cream or whipped cream, if desired.