In a large skillet, heat over medium heat and add the ground beef. Season generously with salt and freshly ground black pepper. Cook until browned, breaking it apart with a spatula for about 8-10 minutes. Add the chopped onion midway through, allowing it to soften and sweeten, around 5 minutes. Drain any excess grease once fully cooked.

Stir in the tomato sauce and tomato paste into the skillet with the browned beef and onions. Add the Italian seasoning, dried parsley flakes, garlic powder, crushed red pepper flakes, Worcestershire sauce, and sugar. Mix everything thoroughly until well combined.

Pour in 1 cup of water into the skillet, mixing well with the sauce. Increase the heat to bring the mixture to a gentle boil, then reduce to a simmer. Allow the sauce to cook uncovered for 30 minutes, stirring occasionally.

As you approach the end of the simmering time, gently fold in the fresh basil leaves. Allow it to simmer for an additional 2-3 minutes.

Once the sauce has thickened and the flavors are well-combined, it's ready to be served. Pour the hearty sauce generously over your choice of cooked spaghetti noodles. Garnish with extra fresh basil if desired.