Preheat oven to 350°F and melt butter in a deep round casserole dish while the oven is heating up.

In a bowl, sift together flour and baking powder; combine with 1 cup of the sugar and milk. Stir until the ingredients are incorporated, and set batter aside.

In a small saucepan, combine remaining 1/2 cup of sugar, peaches, strawberries, blueberries, and lemon juice; simmer on stove for 7-10 minutes.

Pour batter over the melted butter in the warm casserole dish, and then pour the fruit mixture over the batter (but do not stir!!).

Bake for 40 minutes at 350°F or until golden brown.

Serve warm with vanilla ice cream.