Line baking sheets with parchment, foil, or silpat. Preheat your oven to 375.
Whisk together the tomato paste, water, maple syrup, blackstrap molasses, tamari, apple cider vinegar, mustard or mustard powder, chili powder, garlic powder if using, and smoked paprika.
Place the zucchini and chickpeas into a large mixing bowl. Add the barbecue sauce. Toss everything together so that the zucchini and chickpeas are smothered in sauce.
Divide the vegetables onto your prepared baking sheets. Bake for 25-30 minutes, or until the zucchini is tender and the chickpeas are getting crispy.
While the vegetables roast, heat the olive oil in a small frying pan over medium heat. Add the shallots and cook for 2 minutes, or until just tender. Add the corn, along with a pinch of salt and pepper and the lime juice. Saute for 4-5 minutes, or until the corn is sweet and tender but still crisp.
If you're using soft tortillas, warm them in a microwave, over a burner, or pop them in the oven for a minute after the vegetables roast. To prepare the tacos, divide about 1/4 cup filling into each tortilla. Top with two or so tablespoons of corn and a sprinkle of cilantro. Serve.