My notes are showing: "I wouldn't freeze this with the crumb topping on it again, as it tends to slide off. I would wait until I am ready to bake it from the freezer & add the topping fresh." Second note: "I thought that it needed more butter for dotting the top of the crust, so that it would brown evenly.
FILLING: Combine all the ingredients together & set aside. (frozen blueberries, brown sugar, flour, & cinnamon).
CRUST: Combine all the ingredients. (graham cracker crumbs, cinnamon, butter).
Press into a 9-inch square pan that has been lined with heavy-duty foil. This should be a 1-inch thick crust. Bake at 300 degrees F. for 8 minutes.
CRUMB TOPPING: Add all the ingredients except butter. (flour, brown sugar, white sugar, & salt).
TO BRING IT ALL TOGETHER: Put the Frozen Blueberry Mixture into the crust. Top with the Crumb Topping & then dot with the Butter.
AT this point you can toss into the freezer & pull out later. When ready to bake, bake at 350 degrees F. for 55 to 60 minutes. To warm up after initial baking, bake at 250 degrees F. fir 10 to 12 minutes.
The crust being foiled lined is so you can freeze it and once frozen take it out of the baking pan. Then when you are ready to bake it, you will just pop your frozen dessert back into the baking pan. I actually used a deep dish prepared pie crust when making this & it IS not a take a slice like a piece of pie. As it is rich. Truly need to share this to eat with others as it is rich tasting. Next time I will stay true to the recipe as far as the crust. Hope my instructions are not confusing. My recall is a pastry chef was in her kitchen with blueberries and graham crackers and thought those two work well together.