1. Using a vegetable peeler, remove thin layer of peel from lemon, leaving white pith intact. Halve lemon crosswise, and squeeze juice to equal 2 Tbsp. Place lemon juice, lemon peels, brown sugar, next 2 ingredients, and 2 Tbsp. water in a large skillet, and bring to a simmer over medium heat, stirring occasionally. Remove skillet from heat; stir in bourbon and vanilla bean.
2. Return skillet to heat, and add plums, cut sides down. Cook, basting with pan sauce, 3 to 4 minutes or until plums are just tender and lightly caramelized. Remove skillet from heat; discard vanilla bean and lemon peels. Cool 5 minutes. Serve plums and pan sauce with ice cream.
*1 tsp. vanilla extract may be substituted.