Day one
Keep it in the box, out of the sun. A buttercream cake is fine on the counter for a day if the room is cool.
Day two and three
Into the fridge, still boxed. Take it out twenty minutes before you cut so the crumb softens and the frosting loses its chill.
What not to do
Do not wrap a cut cake in foil — it dries the sponge. Press a piece of baking paper against the cut face instead.
