Preparation Position rack in center of oven and preheat to 350°F. Butter 9-inch-diameter springform pan with 2 3/4-inch-high sides. Stir 1/2 cup butter in small saucepan over medium heat until melted and brown, about 3 minutes. Pour into large bowl. Add spice cake mix, canned pear nectar, eggs, molasses and crystallized ginger. Using electric mixer, beat batter 2 minutes. Fold in pears. Pour batter into prepared pan. Bake until cake is dark brown and tester inserted into center comes out with some moist crumbs attached, about 1 hour 10 minutes. Cool cake in pan on rack 15 minutes. Run knife between pan sides and cake to loosen. Release pan sides. Place cake on platter. Stir golden brown sugar, whipping cream and remaining 1/2 cup butter in heavy medium saucepan over medium-high heat until smooth. Boil 3 minutes, stirring often. Stir in pecan halves. Spoon warm topping over warm cake. Serve warm or at room temperature.
Preparation Position rack in center of oven and preheat to 350°F. Butter 9-inch-diameter springform pan with 2 3/4-inch-high sides. Stir 1/2 cup butter in small saucepan over medium heat until melted and brown, about 3 minutes. Pour into large bowl. Add spice cake mix, canned pear nectar, eggs, molasses and crystallized ginger. Using electric mixer, beat batter 2 minutes. Fold in pears. Pour batter into prepared pan. Bake until cake is dark brown and tester inserted into center comes out with some moist crumbs attached, about 1 hour 10 minutes. Cool cake in pan on rack 15 minutes. Run knife between pan sides and cake to loosen. Release pan sides. Place cake on platter. Stir golden brown sugar, whipping cream and remaining 1/2 cup butter in heavy medium saucepan over medium-high heat until smooth. Boil 3 minutes, stirring often. Stir in pecan halves. Spoon warm topping over warm cake. Serve warm or at room temperature.