What happens if you leave a cake out on the counter for several days?

If you leave a cake out on the counter for several days, it may become stale as it loses moisture and its texture changes. Depending on the ingredients and environmental conditions, it could also develop mold or spoil, especially if it contains perishable items like dairy or fruit. To maintain freshness, it's best to store the cake in an airtight container or refrigerate it if it won't be eaten within a day or two.