Freeze 9 inch diameter metal bowl for 2 hours. Remove from freezer and line the interior of the bowl with plastic wrap leaving overhang over the sides.
Spread softened Pumpkin Ice Cream into the bowl (covering the bottom and up the sides) within
½ inch of the top of the bowl. Use a piece of plastic wrap to help press in place.
Return bowl to freezer for 2 hours.
Remove from freezer and repeat with softened Butter Pecan Ice Cream being sure to fill the center of the bowl with ice cream as well as the bottom and up the sides within a ½ inch of the top of the bowl.
Place pound cake slices on top creating a single layer to cover.
Cover with plastic wrap and freeze overnight.
Drizzle with caramel topping prior to serving.
To remove the Bombe from the bowl, place it into a larger bowl of warm water for 5 minutes.
Meanwhile, heat white chocolate chips in a small sauté pan on low until melted. Add whipping cream to white chocolate and stir. Allow cooling slightly.
Use plastic wrap to lift ice cream from bowl and invert onto serving plate. Pour white chocolate over the top and allow to drip down. Sprinkle with nuts and freeze for one hour.