Preheat the oven to 350 degrees F (175 degrees C). Adjust the oven rack to the upper-middle position.
Put butter in an 8-inch square or 9-inch round pan; place in the oven until butter is melted. Remove the pan from the oven and set aside.
Whisk flour, ¾ cup sugar, baking powder, and salt in a medium bowl. Whisk in milk until a smooth batter forms.
Pour batter into the prepared pan with melted butter.
Scatter fruit over batter. Sprinkle with 1 tablespoon sugar.
Bake in the preheated oven until the top is lightly browned and fruit bubbles, 50 to 60 minutes.
Serve warm or at room temperature.
