The first thing you want to do is make the breadcrumbs, this can be done ahead of time. Tear the two slices of bread into 1" pieces and add them to a baking sheet.
Bake the bread at 350 degrees F. for 5-7 minutes, stirring halfway through. Keep an eye on the bread so it doesn't burn.
Once the bread has cooled, add it to a food processor. Pulse until it is a breadcrumb consistency. Measure 1/2 cup of the breadcrumbs.
In a large bowl, mix together the beef, 1/2 cup breadcrumbs, onion, garlic, Worcestershire sauce, egg, almond milk, salt, and pepper until combined. Don't overmix it or the meatloaf will be tough.
Form into a loaf shape and place it on a baking sheet lined with parchment paper.
In a small bowl, mix together the tomato paste, apple cider vinegar, garlic powder, low carb sweetener, salt, pepper, and water.
Spread the mixture evenly over the meatloaf.
Bake at 350 degrees F for 45-60 minutes or until the internal temperature reaches 160 degrees F. Let cool for 10 minutes before serving.