Press the tofu between two plates or clean baking sheets for about an hour, to remove excess liquid and help it to firm up. Cut it into four pieces. Whisk together the tomato paste, 1/2 cup water, maple syrup, blackstrap molasses, tamari, vinegar, mustard, chili powder, garlic powder, and smoked paprika. Pour the barbecue sauce over the tofu, covering each piece well. Allow it to marinate for an hour, or overnight in the fridge.
Preheat your oven to 350F. Line a baking sheet with parchment. Remove the four pieces of tofu from the barbecue sauce, reserving all of the sauce, and place them on the parchment. Use a brush to glaze each piece with extra barbecue sauce. Place the tofu in the oven and bake for 10 minutes. Flip the pieces, brush the other side with extra sauce, and then bake for another 10 minutes (20 minutes total). Remove the tofu from the oven.
To prepare the salsa, mix together the mango, tomato, pepper, onion, vinegar, maple syrup or agave, salt, basil, and mint in a mixing bowl. It can be served right away or allowed to marinate for several hours before serving (it's easy to prepare this a day in advance of the recipe).
To prepare the polenta, bring the 4 cups of water to boil in a medium sized pot. Add the polenta in a thin stream, whisking constantly as you go along, as well as the salt. Reduce the heat to a very low simmer and simmer the polenta, stirring constantly, for 10-20 minutes, or until it's thick and creamy and pulling away from the edges of the pot. Stir in the pepper and Earth Balance or olive oil, if using.
To serve, divide the polenta into four bowls. Top each with a scoop (about 1/3-1/2 cup) of salsa and a piece of tofu. Leftovers will keep for up to two days in the fridge.