Set blackberries in a fine mesh strainer over a measuring cup. If frozen, you'll want to wait 30-60 minutes for them to thaw before pressing to juice.

Preheat oven to 300°F.

Gently press the berries to release juice. Allow to rest while oven preheats so all juice drains out. Discard pulp and seeds.

Add mustard, wine, and maple syrup to the blackberry juice and whisk well to combine.

Score ham with a sharp knife in a criss-cross pattern as this allows for the glaze to penetrate the ham more.

Place in a roasting pan with a quarter inch of water.

With a party brush, glaze the ham and place in the oven. Cook for 15-20 minutes per pound, adding a touch more water if dried out, and glazing during cooking if needed.

Make sure the ham reaches 140-145°F in the center for food safety.

Slice and serve.