Why plastic? Unlike a cardboard box, it keeps out air, which dries both cake and frosting. Toothpicks keep the wrap off the cake (and the presentation pretty), says Megan Ray, co-owner of San Francisco’s Miette Organic Patisserie.
Step 1
Stand the cake slice in the center of a plate. Break off one end of six or seven toothpicks, then insert them, pointy ends down, into the slice— two or three on the top, two on the wide top edge (directed up and slightly outward), and two on the frosted side. Leave about an inch of each toothpick sticking out.
Step 2
Drape a 12-inch sheet of plastic wrap over the toothpick-studded slice. The plastic should extend at least an inch beyond the edge of the plate all the way around.
Step 3
Pull this “tent” down around the plate so it’s slightly taut (you don’t want to rip the plastic or push the toothpicks down). As if you were making a piecrust, press the edge of the wrap firmly onto the plate along its rim, creating an airtight space.