Preheat oven to 350 degrees
In a ziploc bag place all your graham crackers, seal
With a rolling pin, smash all the graham crackers to fine pieces
Pour the graham cracker crumbs into a large bowl
Add the 4 TBS sugar and stir in
Add the zest from 1 lemon and stir in
Pour the 1/2 cup of melted butter over the graham crackers and stir until completely mixed in
In a 9x13 pan pour all the graham crackers and spread to cover the bottom of the pan completely, patting down
Place in a 350 degree oven and bake for 10 minutes
In another large bowl, whip the cream cheese to light and fluffy
Add the 3/4 cup white sugar and cream till smooth
Add the zest from 3 lemons and the lemon juice
Beat until the cream cheese, sugars, and juice are creamed together well
Spread over the top of the graham cracker crust
Spread the cherry pie filling over the cream cheese layer (you might choose to use only the sauce from 1 1/2 can but use all the cherries from both cans)
In another medium to large bowl put your brown sugar, oats, and flour - mix together
Using your fingers or a fork add the softened 1/2 cup butter and combine with the brown sugar, oats, and flour until crumbly and well mixed in (hopefully crumbs to about pea size)
Spread the streusel topping all over the cherries
Bake in the 350 degree oven for 35 to 40 minutes until the streusel topping is golden brown and the cheesecake filling is mostly solid
Place on a cooling rack for 1 hour
Place in refrigerator to chill for 2 or more hours
Serve chilled