Mark Lewis, the founder of Marco Paolo Chocolates, produces boxes of double-layered truffles with exotic flavor combinations—think white chocolate and coconut ganache paired with cilantro and a dark chocolate and lime ganache, or pomegranate and white chocolate ganache married with dark chocolate and an aged balsamic reduction. “The primary challenge in a double-layered truffle has been finding combinations of flavors that work,” he explains. “The two layers have to be complementary yet contrasting flavors and…