Heat oven to 350 degrees. In small saucepan over low heat, combine brown sugar, butter, and 2 tablespoons whipping cream. Cook and stir just until butter is melted. Remove from heat; stir in pecans. Pour mixture into bottom of ungreased 9-inch round cake pan or 9-inch square pan. Set aside.
In large bowl, combine all cake ingredients. Stir 50-75 strokes by hand until mix is moistened. Carefully spoon batter over the caramel mixture, making sure caramel is completely covered. Bake at 350 degrees for 40-50 minutes or until toothpick inserted in center comes out clean. Cool 1 minute; invert onto serving plate. Cool.
Just before serving, in small bowl beat remaining whipping cream until soft peaks form. Add powdered sugar and whiskey. Beat until smooth peaks form. Spread whipped cream mixture on top of cake. Sprinkle lightly with cinnamon. Store in refrigerator.