Go right ahead and freeze the cupcakes if you want. You can freeze them before you slice and assemble them in a jar. Or after, just place lid on the jar and leave of the Rice Krispies treat, or place the whole treat in an airtight container. u003cbr/u003eCupcakes will freeze 3-4 months. Thaw in the fridge in an airtight container in the fridge.