I just made this pound cake and will be serving it tomorrow.
How should I store it overnight?
I would cover it with plastic wrap and keep it on the counter.
Agreed, and I would wait for it to cool uncovered for a little so there's not lots of condensation on the inside.
May I respectfully suggest that you remove the cake from the pan right now if you have not already? The recipe says to remove it after 15 minutes. I've found that cakes, quick breads, etc. not removed as soon as it's safe to do so (cooled enough to maintain integrity of the crumb, etc.) can stick hard to the pan, making removal a lot more difficult. If you're confident that you're non-stick pan won't let you down, then so be it. But I would not take any chances . . . . and I'd put the cake on a plate and tightly wrap once fully cooled, as in, at least 3 or 4 hours after removing from the oven. ;o)