1. Arrange 12 paper liners in a 12-cup muffin tin. Cut pound cake into 1/2-inch-thick slices. Use a 2-inch biscuit cutter to cut 12 circles from slices, reserving scraps for another use. Place circles in bottoms of cupcake liners.
2. Combine heavy cream and confectioners' sugar in a bowl and whip with an electric mixer until cream holds stiff peaks.
3. Scoop ice cream into a large bowl. Reserve 1/4 cup Heath Bar Bits; add remaining Bits to bowl with ice cream. Combine by mashing ice cream and candy with back of a large spoon. (If ice cream gets too soft, place bowl in freezer for 10 minutes before continuing.)
4. Top each pound-cake circle with a scoop of ice cream and cover with whipped cream. Sprinkle with remaining Heath Bar Bits. Lightly drape cupcakes with plastic wrap and place in freezer until firm, at least 2 hours or up to 3 days.