Preheat the oven to 400 degrees F. In a small bowl, whisk together the sugar and cinnamon.
In another bowl, toss the plums, apricots, vanilla extract, and orange juice together.
In a roasting pan or oven-proof baking dish, arrange the fruit cut-side up pouring any extra juice in the baking dish. Sprinkle evenly with the cinnamon-sugar mixture.
Roast for 15 to 20 minutes or until the fruit is fork tender.