SAVANNAH — While many college students typically study hard for final-exam questions, Savannah Technical College’s culinary arts baking and pastry students spend weeks working on their cake-decorating final exam. Their assignment was to create two-tier wedding cakes that demonstrated at least eight decorating techniques. This summer, after cakes were scored for the final-exam grade, a panel of judges picked Richmond Hill High School senior Rachel Peeples’ work as the best.