Cinnamon Apple Crisp Muffins are topped with a slightly crunchy cinnamon topping.
Baked goods seem to be made for freezing.
After they have cooled you may freeze them in any of the methods shown in my article How to Prepare Food for the Freezer
They defrost quickly so it really doesn't take any planning.
Just take them out of the freezer and set in the refrigerator. You can even set them on a platter if you are serving them for breakfast or a treat in about an hour.