Pour 4 quarts of water into a 6-quart stock pot, add 1 tablespoon kosher salt, cover with the lid, and heat on high until a rolling boil.
Preheat the oven to broil and line a baking sheet for the garlic bread.
In a large skillet over medium heat, warm 2 tablespoons vegetable oil.
Add the ground beef, break it into small pieces, season with 1 teaspoon kosher salt, and cook, stirring and breaking up lumps, until no longer pink.
Stir the entire 24 oz jar of Ragu sauce into the cooked beef, then add 1 teaspoon garlic powder, 1 teaspoon onion powder, and 1 teaspoon ground black pepper; reduce heat to low and keep warm while the pasta cooks.
Arrange the 4 slices of bread on the baking sheet and top each with a pat of butter; sprinkle the bread with the remaining 1 teaspoon garlic powder and 1/2 teaspoon kosher salt.
When the pasta water is at a rolling boil, add the 1 pound of spaghetti and gently push it down with a wooden spoon until submerged; leave the lid slightly ajar to prevent boiling over and reduce heat to medium once the boil returns.
Cook the pasta 9–10 minutes or according to package directions, stirring frequently to prevent sticking.
About 3 minutes before the pasta is done, place the garlic bread under the broiler and watch closely; remove when toasty and the butter has melted.
Drain the pasta in a strainer, return it to the stock pot, and serve topped with the beef and Ragu sauce and the garlic toast.
