Melt butter in a large frying pan over medium heat. When it starts to bubble, add brown sugar, stone fruit, and ginger, tossing slightly to coat. Cook until fruit is softened and juices are released, stirring occasionally, about 4 minutes. Add in a dash of Gran Marnier.
Toast pound cake until warm and slightly golden, about 2 minutes.
Put a cake slice into each of 4 bowls and top with ice cream and the warm fruit.
Out of season, you can use frozen fruit. Cook the fruit less to avoid over softening the fruit.