Store in an airtight container at room temperature for up to 3 days, or refrigerate for up to 5 days.
Bars can be frozen for up to 2 months; thaw before serving.
Variations
Add chopped walnuts or pecans to the crumble topping for extra crunch.
Swap apples with pears or a mix of apples and berries for a fruity twist.
Drizzle with caramel sauce for a richer dessert.
