Lightly grease an 8x8x2-inch square baking pan. Set aside.
In a large bowl, combine flour, the granulated sugar, baking powder, cinnamon, baking soda, and salt. Using a pastry blender, cut in the 1/2 cup butter until mixture resembles coarse crumbs. Stir in currants. Combine milk, sour cream and egg; add to flour mixture. Stir just to moisten. Spread the dough in prepared pan. Bake in a 450 degree F oven for 15 to 20 minutes or until a wooden toothpick inserted near the center comes out clean. Cool in pan for 10 minutes. Remove from pan.
Meanwhile, prepare the topping:
In a large skillet, melt the 2 tablespoons butter over medium heat; stir in the brown sugar and nutmeg until combined. Add pears. Cook, uncovered, for 5 minutes, stirring occasionally. Add cranberries. Cook, uncovered, for 3 minutes more or until cranberries pop. Remove from heat. Let stand for 5 minutes.
Serve the shortcake warm topped with fruit mixture and whipped dessert topping. Makes 6 to 8 servings.