PreparationFor pears: Melt butter in heavy large skillet over high heat. Add pears; sauté 1 minute. Add both sugars and wine and stir until sugar dissolves. Scrape out seeds from vanilla bean and add to skillet; add bean. Boil until pears are tender and juices in skillet form thick syrup, about 5 minutes. Remove from heat. Cool. Discard vanilla bean. (Can be made 1 day ahead. Cover; chill.) For zabaglione: Whisk yolks, sugar, Tuaca, and 2 tablespoons cream in large metal bowl to blend well. Set bowl over saucepan of simmering water (do not allow bottom of bowl to touch water). Using electric mixer, beat yolk mixture constantly until mixture thickens and instant-read thermometer inserted into mixture registers 140°F for 3 minutes, about 7 minutes total. Remove bowl from over water; place bowl in larger bowl of ice water. Whisk occasionally until mixture is cool, about 3 minutes. Using electric mixer, beat remaining 1 cup cream and cinnamon in medium bowl until peaks form. Fold 1/3 of whipped cream into yolk mixture, then fold in remaining cream in 2 additions. Chill until cold. (Can be prepared 1 day ahead. Cover and keep refrigerated.) Divide pears among 6 dessert glasses. Spoon zabaglione over each. Dust with powdered sugar and serve.
PreparationFor pears: Melt butter in heavy large skillet over high heat. Add pears; sauté 1 minute. Add both sugars and wine and stir until sugar dissolves. Scrape out seeds from vanilla bean and add to skillet; add bean. Boil until pears are tender and juices in skillet form thick syrup, about 5 minutes. Remove from heat. Cool. Discard vanilla bean. (Can be made 1 day ahead. Cover; chill.) For zabaglione: Whisk yolks, sugar, Tuaca, and 2 tablespoons cream in large metal bowl to blend well. Set bowl over saucepan of simmering water (do not allow bottom of bowl to touch water). Using electric mixer, beat yolk mixture constantly until mixture thickens and instant-read thermometer inserted into mixture registers 140°F for 3 minutes, about 7 minutes total. Remove bowl from over water; place bowl in larger bowl of ice water. Whisk occasionally until mixture is cool, about 3 minutes. Using electric mixer, beat remaining 1 cup cream and cinnamon in medium bowl until peaks form. Fold 1/3 of whipped cream into yolk mixture, then fold in remaining cream in 2 additions. Chill until cold. (Can be prepared 1 day ahead. Cover and keep refrigerated.) Divide pears among 6 dessert glasses. Spoon zabaglione over each. Dust with powdered sugar and serve.