Heat oven to 350. Spray 9 or 10 inch springform pan with nonstick cooking spray. In small saucepan, combine filling ingredients. Cook over medium-low heat until chocolate is melted, stirring occasionally.
In large bowl, combine cake mix, cinnamon and oil; blend at low speed for 20-30 seconds or until crumbly. (Mixture will be dry) Place pears in blender container or food processor bowl with metal blade; cover and blend until smooth
In large bowl, combine 21/2 cups of the cake mix mixture, bureed pears and eggs; beat at low speed until moistened. Beat 2 minutes at medium speed. Spread batter evenly in sprayed pan. Drop filling by spoonfuls over batter. Stir nuts and water into remaining cake mix mixture. Sprinkle over filling.
Bake at 350 for 45 - 50 minutes or until top springs back when touched lightly in center. Cool 10 minutes. Remove sides of pan. Cool 11/2 hours or until completely cooled.
In small saucepan, combine sauce ingredients. Cook over medium-low heat for 3-4 minutes or until well blended, stirring occasionally. To serve, spoon 11/2 tbsp warm sauce onto each serving plate, top with wedge of torte and scoop of ice cream. If desired, garnish with chocolate curls.