In a 3- to 4-qt. pan over high heat, boil wine, orange juice, 1/2 cup sugar, and the cardamom, stirring often, until reduced to 2/3 cup, 10 to 15 minutes. Remove from heat, stir in plums, and let stand 10 minutes, stirring often. Meanwhile, whip cream with the remaining 2 tbsp. sugar until thick.
With a slotted spoon, lift 3 or 4 plum slices to each of 4 small bowls. Top each with 1 broken cookie, then a spoonful of cream. Repeat layers 2 more times. Serve trifles with syrup and any remaining fruit.