Cut tofu across on the shortest side, so it's halved into rectangles the size of the entire area. Like the way you would slice a bagel. Wrap in clean kitchen towel and place something heavy on top to help press out the liquid. Alternately, use a tofu press.
Preheat oven to 400 degrees and line rimmed baking sheet with unbleached parchment paper.
Prep veggies: cut broccoli into florets, cut red pepper into strips and onion into thin slices.
Make tofu marinade: Use fork to mix 2 tblsp of the olive oil, maple syrup, garlic powder, onion powder, smoked paprika, salt and arrowroot powder together.
Take the two halves of the tofu and cut through again (like slicing a bagel) so now you have 4 pieces. Place them on the prepared baking pan and score the tops---carefully so you don't cut all the way through. Baste with the marinade, pushing some into the crevices created with the cuts. Then flip over and baste the other side.
Sprinkle prepared vegetables all around the tofu, drizzle with remaining 1 tablespoon of olive oil and sprinkle with salt and pepper.
Bake for 10 minutes. Remove from oven and spread 1-2 tablespoons bbq sauce onto each piece of tofu. Return to oven and cook for another 10 minutes.
Serve with remaining ¼ cup bbq sauce.
Notes
BBQ Sauce: Use this recipe for homemade bbq sauce or read labels of the bottles of bbq sauce from the grocery store to find ingredients that work well for your dietary preferences. Use any vegetables that you like, but add those with shorter cooking times (like asparagus or zucchini) to the sheet pan when you add the bbq sauce so they don't get overcooked. BBQ SAUCE: In a small bowl, mix together ¼ cup tomato paste, 2 tablespoon apple cider vinegar, 1 tablespoon date syrup, 2 teaspoon dijon mustard, 1 teaspoon worcestershire sauce, 1 teaspoon cacao powder, ¼ teaspoon smoked paprika, ¼ teaspoon chili powder, ¼ teaspoon garlic powder, ¼ teaspoon sea salt. Then add ¼ cup water and mix until well incorporated.