Preheat oven to 400°F. Line a large rimmed baking sheet with parchment paper. Lightly grease a casserole dish. Set both aside.
In a bowl, combine jackfruit with buffalo sauce and lemon juice. Transfer to the greased casserole dish and bake for 10-15 minutes. Remove from oven and allow to cool slightly. Use two forks to shred the jackfruit and stir so it can absorb more of the sauce.
To assemble pizza, place the crust on the lined baking sheet and top with the buffalo jackfruit. Add the onion and bell pepper. Bake for 10-15 minutes, or until crust is deeply golden and the vegetables are tender. Remove from oven.
Top the pizza with sliced avocado, minced parsley, and green onions. Serve with Cashew Ranch Dipping Sauce on the side.
To make Cashew Ranch Dipping Sauce: soak 1/2 cup raw cashews in water for several hours or overnight. Drain and rinse. Place in blender with 2 teaspoons lemon juice, 1/2 teaspoon dried dill weed, 1/4 teaspoon garlic powder, a pinch of paprika, and a good pinch each salt and freshly ground black pepper. Add a few tablespoons of water and blend until smooth. Store in fridge until ready to use.
This pizza is best eaten the day it is baked, but will keep for 1-2 days in the fridge.