Preheat the oven to 375°F. Line a 9x5-inch loaf pan with parchment paper, leaving a little extra hanging over to use as "handles" after baking.
In a large bowl, using a potato masher or by hand, mash the black beans; a little chunkiness is good.
Add the cooked quinoa, breadcrumbs, olive oil, chili powder, smoked paprika, onion powder, garlic powder, seasoned salt, and ground cumin; continue mixing to combine thoroughly.
Add 1/4 cup ketchup and parsley. Miix one more time to distribute ketchup and parsley throughout.
Transfer the entire mixture to the prepared loaf pan, pressing to ensure it is packed in firmly. Bake for 45 minutes.
Meanwhile, prepare the glaze: In a small bowl, whisk together the remaining 1/4 cup ketchup with brown sugar and mustard powder. Set aside.
When the loaf has finished its 45 minutes of baking, carefully remove it from the oven and spread the ketchup glaze over the top to cover it completely. Return the loaf to the oven and continue baking for an additional 10 minutes to set the glaze.
After removing from the oven, allow the loaf to stand for 10 minutes in the hot pan then, using the excess parchment paper on each side, lift it out of the pan and set on a flat surface. Cut into 1-inch slices and serve warm.