1.Peel pears, leaving stems intact.
2.Combine Champagne, sugar, rind and rosewater in 4.5-litre (18-cup) slow cooker. Halve vanilla bean lengthways, scrape seeds into cooker; add bean.
3.Lay pears down in cooker to submerge in champagne mixture. Cook, covered, on high, about 4½ hours or until pears are tender.
4.Place 1 cup of the poaching liquid in small saucepan; bring to the boil. Boil, uncovered, about 7 minutes or until syrup is reduced by about half; cool.
5.Place pears in large deep bowl; add remaining poaching liquid, cool.
6.Serve pears drizzled with syrup.
Store any leftover poaching liquid in the refrigerator for up to 1 month. Use for poaching more pears or stone fruit. We used packham pears in this recipe.Note