Preheat a grill or grill pan to medium-low. Brush the pound cake slices with melted butter. Grill until the cake is toasted, about 2 minutes on each side. In a small saucepan over medium-low heat, combine the berries, the lemon juice, and sugar. Cook until the berries have become soft and have begun to release juice , about 10 minutes. You can serve the sauce atop each slice, or sandwich it in the middle of two slices. If desired, serve with ice cream.
