Most fruit based desserts need to be u003ca href=u0022https://www.cooksillustrated.com/how_tos/11458-how-to-store-leftover-fruit-pieu0022 target=u0022_blanku0022 rel=u0022noreferrer noopeneru0022u003erefrigerated after bakingu003c/au003e. You can get by with it for two days, but after that, the fruit can spoil if left at room temperature. Once refrigerated, the crumble won't be as crisp, so reheat in a 350 degree oven for best results.