Heat oven to 350°F. Grease and flour 10-inch tube pan. Drain 1 can pear halves, reserving 1/3 cup liquid. Place pear halves in food processor bowl with metal blade or blender container; cover and process until smooth.
In large bowl, combine cake mix, pureed pears, reserved 1/3 cup pear liquid, oil and egg whites; beat at low speed until moistened. Beat 2 minutes at medium speed. Pour into greased and floured pan.
Bake at 350°F. for 40 to 45 minutes or until toothpick inserted in center comes out clean. Cool cake upright in pan 15 minutes. Invert onto serving plate. Cool 1 1/2 hours or until completely cooled.
Meanwhile, in medium saucepan, combine all sauce ingredients; mix well. Bring to a boil. Boil over medium heat 5 minutes, stirring occasionally. Remove from heat; cool to room temperature.
In small bowl, beat 1 cup whipping cream and sugar until stiff peaks form. Fold in pear brandy. Frost cooled cake with whipped cream. Cut drained pear halves lengthwise into about 32 slices. Arrange on top of cake, slightly overlapping slices. Press nuts into sides of cake. Drizzle 2 tablespoons sauce over pear slices. Refrigerate until serving time.
To serve, spoon about 2 tablespoons sauce onto each individual dessert plate. Top each with slice of cake. Store cake and sauce in refrigerator.