Drain peaches, reserving juice. In a small saucepan combine apricot or strawberry preserves, margarine or butter, lemon juice, and enough reserved peach juice to make a slightly thickened sauce (1 to 2 tablespoons).
Bring mixture just to boiling over medium-high heat, stirring constantly. Reduce heat; stir in peach slices, banana slices, and, if desired, brandy; heat through. Serve warm. Cover and refrigerate remaining topping for up to 24 hours. Makes 2 cups.