Well, I was having one of those moments, and I got my thinking cap out, and here's what I came up with. And by jove, it's quite good. The amounts are for one tart (probably two servings), but it would be quite easy to double.
Apple tart with stale pita crust
1 dry pita (it's probably fine if it's not dry also)
1-2 tsp. margarine
1/2 lb. firm tofu
2 Tbsp. lemon juice
1/4 cup maple syrup or sweetener of choice (you may want to add a little water or soy milk if you use a dry sweetener)
1 Tbsp. oil (optional)
1/2 to 1 sweet apple, chopped into bite-sized pieces
1/4 cup walnut or other nut pieces (optional)
Preheat oven to 350F. Spread one side of the pita with the margarine (if the pita has dried in a cup shape you should do the outside of the cup). Put it in a cake or pie pan, buttered side down. Put tofu, lemon juice, sweetener, oil, salt, and spices into a food processor or blender and process until smooth. Add the apple and pulse until it's incorporated and chopped into small bits but not blended. Spread thickly (about 1/2") on the pita. Sprinkle on the walnuts. Bake about 20 minutes or until filling is set and slightly golden around the edges. You will probably need to cover it to keep it from browning too much at the edges. Cut into wedges and serve warm.