The night before, cut the 3 bananas into chunks, put them in a freezer-safe plastic bag, and freeze them.
Preheat the oven to 350 °F and lightly coat a pie plate (or pie dish) with nonstick spray.
Make the pie crust: Crush the graham crackers by putting them in a sealed plastic bag and rolling over them with a rolling pin. Add the cinnamon and orange juice and mix until you have a "dough." Press the dough into the bottom of the prepared pie plate and bake for about 15 minutes, until the crust turns lightly golden-brown.
Make the banana soft-serve: Combine the frozen banana chunks, milk, ¼ cup sugar, 1 teaspoon vanilla extract, 1 teaspoon lemon juice and a small pinch of salt in a food processor and blend until smooth.
Stir in the crushed pineapple.
Transfer the banana soft serve to the pie plate, and spread evenly with a spatula. Put the pie plate into the freezer for a bit while you make the strawberry fro-yo layer.
Make the strawberry froyo: Put the frozen strawberries, Greek yogurt, ¼ cup sugar, 1 teaspoon vanilla extract, 1 teaspoon lemon juice and a tiny pinch of salt into the food processor and blend until smooth.
Spread the strawberry mixture on top of the banana layer.
Top with 8 whole strawberries, and return to the freezer for several hours.
If you want, you can mix 1 tablespoon unsweetened cocoa powder + 1 tablespoon maple syrup to drizzle over the top just before serving.