04Pour custard into pan with syrup. Place loaf pan in large roasting pan. Add enough hot water to roasting pan to come halfway up sides of loaf pan. Cover roasting pan with foil. Pierce foil all over with fork. Bake flan 1 hour 45 minutes. Increase oven temperature to 325°F. Uncover and bake until flan is set around edges but center moves slightly when pan is gently shaken, about 1 hour longer. Remove flan from water. Transfer to rack; cool to room temperature. Cover and refrigerate overnight.
05Preheat oven to 375°F. Melt butter in heavy large ovenproof skillet over medium-high heat. Arrange pears, 1 cut side down, in skillet. Cook until brown, about 4 minutes. Turn onto second cut side and cook until brown, about 4 minutes longer. Stir in maple syrup; bring to boil. Place in oven and bake until pears are tender, about 25 minutes. Using slotted spoon, transfer pears to plate. Whisk crème fraîche and salt into sauce in skillet. Return pears to skillet and toss to coat.
06Run sharp knife around edge of flan to loosen. Invert flan onto platter. Surround with pears and sauce.