Grease 9" springform or round cake pan 1 1/2" deep. Melt 2 tb butter with brown sugar in 10" skillet over medium heat. Add apple slices. Cook over medium heat until apples begin to soften, about 4 minutes, stirring often. Arrange apples in even layer over bottom of prepared cake pan. Set aside to cool. Cream remaining 1/2 c butter and granulated sugar until light. Add egg. Beat until smooth. Add applesauce and blend well. Combine flour, baking soda, cinnamon, nutmeg and salt in small bowl. Add to creamed mixture. Mix until smooth. Spread batter evenly over apples. Place pan on baking sheet. Bake on middle rack of 350~ oven until wood pick inserted in center comes out clean, about 40 to 45 minutes. Cool on rack 15 minutes. Use small flexible knife to separate cake from sides of pan. Invert pan on serving platter and unmold cake (replace any apple slices that may remain in pan). Serve warm. Pass CINNAMON CREAM TOPPING in separate dish. Beat cream cheese and sour cream until smooth. Gradually add cinnamon, then sugar, mixing well after each addition until smooth. Let stand 15 minutes at room temperature before serving.