Apple Caramel Glaze

1 1/4 cups firmly packed brown sugar
1/4 cup apple juice or cider
2 heaping tablespoons flour
1/2 teaspoon cinnamon
1/2 teaspoon prepared or dry mustard
1/4 teaspoon ground allspice

Combine all ingredients and mix until smooth. Coat ham generously before cooking and every 30 minutes while roasting.