Fresh raspberries and blueberries can be stewed in minutes; they make a delicious topping for vanilla ice cream. Framboise, raspberry-flavored liqueur, adds extra zing.
Combine 2 half-pints raspberries with the blueberries, sugar, and 3/4 cup water in a medium saucepan. Bring to a boil, and cook uncovered over medium to low heat, stirring occasionally, until the sugar is a syrup and the berries have released their juices, 10 to 12 minutes. Remove from heat, and stir in the remaining half-pint of raspberries and the Framboise, if using.
Place 3/4 cup stewed berries in a bowl. Add a large scoop of ice cream to each bowl, and serve immediately.