Preparation

• Heat the oven to 425°F. Cut the plums in half, discard the pits, and slice the halved plums into four wedges each. Generously butter an 8×11-inch baking dish (or one just large enough to hold the plums).
• In a mixing bowl, toss the plums with 3 Tbs. of the sugar, the lemon zest, lemon juice, rum, vanilla, ginger, and salt. Toss well. Taste one of the plum wedges; if it’s still tart, sprinkle in the remaining 1 Tbs. sugar. Pour into the baking dish and roast, gently stirring occasionally, until the plums are tender and juicy, 10 to 20 minutes. Don’t overcook them or they’ll fall apart.
• Let the plums cool for at least 5 minutes or up to an hour before serving. Serve the plums hot or warm with vanilla ice cream and spoon the juices over the top.