Preheat your oven to 350°F (175°C).
Place the butter in a 9x13-inch baking dish and melt it in the oven.
In a mixing bowl, combine flour, sugar, baking powder, and salt. Stir in the milk until smooth.
Pour the batter evenly over the melted butter—do not stir.
Spoon the fruit along with juice (if using canned) evenly over the batter—again, do not stir.
Bake for 45 to 55 minutes or until the top is golden and cooked through.
Let it cool slightly before serving. Delicious warm or cold!