Graham crackers: I am planning on making key lime pie this week and I also need graham crackers. My plan is to pick up some of these IMEI crackers as I’ve noticed they have a similar taste and texture to graham crackers:
Hopefully they will not be too crumbly, but I figure any kind of lightly sweetened cracker or cookie that you can crush up and add melted butter to should be a good substitute. I’ve made a gluten-free “graham cracker” crust with Chex cereal before and it turned out all right.
Lemon pudding mix: Vanilla pudding mix plus lemon zest and juice? Or homemade lemon pudding if you can’t find any pudding mix at all.
Cool whip: You can make it from scratch, perhaps using this recipe: Homemade Cool Whip
I was going to suggest the same. It’s more work but shocking how much better it will be. I learned how to cook in Taiwan. One of my favorite combinations is a cheesecake with coconut cookie crust topped with lillikoi or guava syrup.
Yeah, make the lemon pudding with the three cups of milk and use that. Alternately, mix ingredients seem to be just sugar, cornstarch, and flavor, and there are some ideas about proportions online.
Ditto on Mcvitie Digestive Biscuits, easy to get and close enough.