For the finale, pastry chefs Buddy Valastro and Duff Goldman head to the Food Network Kitchen to create their most heartfelt and monumental creations yet -- chocolate desserts to conceal engagement rings for two surprise proposals. For the final cake... (more)-off, Buddy and Duff create jaw-dropping science- and space-themed cakes for Philadelphia's prestigious Franklin Institute. Street Science host Kevin Delaney presides over the wild festivities as Buddy and Duff lay it all on the line with their showstopping masterpieces.