Thaw pound cakes and slice about 1/2 inch thick. Whip both whipping creams; add crushed Heath bars to whipped cream (save enough to sprinkle top of cake for decoration).
Layer cake in cake dish. Spread whipped cream mixture across cake to cover. Repeat, place second layer of cake and spread remaining whipped cream mixture. Sprinkle with crushed Heath bar.
To crush Heath bars, try using a hammer and put Heath bars in a Ziploc bag.