First pre-heat oven to 350F. Then in a 1 quart saucepan stir together the butter, whipping cream & briwn sugar. Cook over low heat, stir occasionally just until the butter is melted. Then pour into 2 ungreased 9 or 8 inch round cake pan. Then sprinkle evenly with 3/4 cups of the nuts.
Next in a large bowl beat the cake mix, pumpkin, water, oil, eggs & 1 tsp. spice with an eletric mixer on low speeduntil moistened, then on medium speed for about 2 mins. Make sureto scrape the bowl occasionally. Then carefull spoon the batter over the nut mixture in each pan.
Next bake for about 41 to 45 mins or until cake is springy when lightly touched in the center. Let cool for about 5 mins. Remove for the pans & full cool about 1 hour.
Then stir in the remaining pumpkin spice into the frosting. Place 1 layer, nut side up on a serving plate. Spreadhalf the frosting,then press second layer on top of first layer nut side up. Spread remaining frosting just to the edge. Then drizzle with the caramel topping & additional nuts.