Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
Heat the olive oil in a medium pot over medium heat. Once the oil begins to shimmer, add the yellow onion and cook for 4-5 minutes, until semi-translucent. Add the garlic and cook for another 2-3 minutes, until fragrant. Add the jackfruit, salt, pepper, chili powder, paprika, cumin, and liquid smoke and stir until the jackfruit is well coated in the spices. Add the vegetable broth, cover, and cook for 15 minutes, until the jackfruit is tender enough to be mashed.
Mash the jackfruit until mostly broken apart and stringy. Transfer to a baking sheet and spread in an even layer. Bake for 20 minutes, until lightly browned.
Use your hands to stretch the pizza dough into a circle about 14 inches (35 cm) in diameter and ½-inch (1 ¼ cm) thick. Lay on a sheet of parchment paper.
Remove jackfruit from oven and increase the oven temperature to 425°F (220°C).
Pour ½ cup (145 g) of vegan barbecue sauce over the jackfruit, then toss to coat.
Spread the remaining ¼ cup (72g) barbecue sauce over the pizza dough in an even layer. Top with the jackfruit and red onion.
Bake for 14-16 minutes, until the crust is lightly golden around the edges.
Remove the pizza from the oven. Drizzle with the vegan ranch and garnish with cilantro leaves. Cut into 8 slices and serve.