Let the ice cream sit out on the countertop at room temperature for about 1/2 hour until it becomes soft, but not runny. (Time will vary depending on the temperature of your house and the size of the ice cream containers).
While the ice cream is softening, make the crumb crust.
For the crumb layer bottom
Crush the graham crackers (or cookies) by putting them in a zip lock bag and hitting them with a wooden spoon until they are crumb size. You can also put them in a food processor and pulse them a few times until they are ground up.
Pour the graham crackers into the bottom of the baking dish. Then drizzle them with 1/2 cup of melted butter.
Mix the graham crackers, and butter well, then press it firmly to the bottom of the dish with your hands or the bottom of a measuring cup and place in the fridge.
For the ice cream layer
Scoop the softened ice cream into a mixing bowl and add the zest and juice of 2 fresh lemons and then use a mixer to blend the lemon juice with the ice cream.
Spread the blended ice cream over the crumb crust and smooth it out until it is even.
Cover with plastic wrap and freeze for at least 4-5 hours until the ice cream is firm again. (I like to make it a day ahead and freeze it overnight.)
Top it with sliced berries or fruit or decorate it with vegan whipped cream, frosting, or sprinkles just before serving.
Allow it to warm up for 5-15 minutes before serving so that the ice cream becomes soft enough to cut into pieces.
Notes
Just allow the ice cream to soften to the point where it can be blended, not so much that it is melted.
Place the fruit on top just before serving. If you freeze it with the ice cream, it will become too hard.
Cut with a large sharp knife and push down firmly. If it is too frozen to cut, wait a few minutes and try again.