In a food processor, purée 2 cups blackberries with brandy and orange juice. Transfer to a sieve and press out juice, discarding the seeds.
Stir remaining whole berries into sauce just before serving. Serve over ice cream or pound cake.
Notes
Blackberries are naturally sweet and juicy. In this sauce, they are combined with orange juice and a touch of brandy for a delightful complement to ice cream or pound cake.