Add the chopped onion and crushed garlic to a frying pan with the olive oil and sauté until the onions are softened.
Preheat the oven to 375°F (190°C). Spray a loaf pan with non-stick spray and line it with parchment paper so that the meatloaf can be easily lifted out. Set aside.
Drain the chickpeas and add to a mixing bowl. Mash with a fork or potato masher until roughly mashed.
Make your breadcrumbs by breaking up the 4 slices of bread and placing into a blender and pulse blending until it makes breadcrumbs (see notes*).
Add the breadcrumbs, soy sauce, sweet chili sauce, dijon mustard, flaxseed meal, nutritional yeast, garlic powder, tomato paste and cayenne pepper to the mixing bowl. Add in the cooked onions and garlic. Mix very well into a thick batter. Make sure everything is evenly mixed (it's a very thick mix). Transfer this into the parchment lined loaf pan and smooth down with the back of a spoon.
Cover with foil and bake for 30 minutes.
While the meatloaf is baking, mix the tomato paste, brown sugar, maple syrup, garlic powder, salt and paprika in a bowl and stir together.
When the meatloaf has baked for 30 minutes, remove it from the oven and remove the foil. Spread on the tomato glaze evenly and return it to the oven, (no foil, uncovered) to bake for a further 15 minutes.
Remove from the oven and allow to cool for at least 10 minutes before removing from the loaf pan by lifting the meatloaf out with the parchment paper. Let it cool for another 10 minutes.
Slice and serve with fresh basil.