Preheat oven to 375 F. Line 9 inch loaf pan with parchment paper, leaving 1 inch overhang.
Place black beans in large bowl and mash with potato masher or fork. Add meatless grounds, oat bran, carrot, 1/4 cup tomato paste, soy sauce, oregano, cumin powder, chili powder, garlic powder, and onion powder. Place half of mixture in prepared pan and press down firmly for even layer. Add remaining bean mixture to pan and press down firmly for even layer. Cover pan and bake for 30 minutes.
In small bowl, stir together remaining 2 Tbsp tomato paste, maple syrup, vinegar, and paprika.
After 30 minutes, remove loaf pan cover, spread tomato-maple topping evenly on loaf, and bake for another 15 minutes, uncovered.
Allow loaf to sit for at least 15 minutes before using parchment paper to lift out of pan.