*You can use any shortbread or sandwich cookie you like. In such a case you may have to reduce the amount of butter used. Start with half the butter, check the crumbs then add a little more at a time checking the crumbs as you go. To test if you have enough butter, scoop a bit of the mix into your hands and squeeze it together, it should hold together on its own when you let it go.
**Reduce to 1/2 cup if a firmer, less airy pie is desired
To substitute gelatin:
You won’t need to boil the gelatin in the same way you do for the agar flakes. Sprinkle them gelatin over half the amount of milk and let bloom. Once the sugar in the other half of the milk has dissolved, add gelatin-milk mix and heat till the gelatin melts. Proceed with the recipe.