Preheat oven to 350 degrees F. In a large mixing bowl, cream butter and sugar together until light and fluffy. Add eggs, vanilla and AE Sour Cream. Beat for 30 seconds to 1 minute until well blended. Sift together flour, baking soda, baking powder, and salt. Stir in dry ingredients gently, do not overmix. Delicately fold in chopped pears. Pour into greased 9x13 baking dish. Set aside. Meanwhile, mix together nuts, cinnamon, brown sugar, flour and cold butter until a coarse mixture forms. Sprinkle on top of batter. Bake at 350 F for 50-55 minutes until a cake tester comes out mostly clean and the cake is well browned. Remove from oven, let cool to warm before serving. Garnish with lightly sweetened, freshly whipped AE Heavy Whipping Cream. (recipe follows) *Combine 1 cup of well chilled AE Heavy Whipping Cream, 1-2 tablespoons sugar and 1 teaspoon vanilla extract in a medium sized mixing bowl. Whip until soft to medium peaks form. Spoon over pear cake prior to serving.