Heat a large skillet over medium-high heat and add 1 pound ground beef, breaking it up as it cooks. Brown the meat for 5 to 6 minutes until no pink remains.

Drain excess fat from the skillet, leaving about 1 tablespoon for flavor.

Pour the entire can of tomato sauce into the skillet with the beef and stir until evenly combined.

Sprinkle 3 tablespoons brown sugar over the mixture and stir well to dissolve and coat the beef.

Reduce heat to medium-low to prevent splattering and allow flavors to meld.

Let the mixture simmer for 5 to 7 minutes, stirring occasionally, until the sauce thickens slightly.

Taste and season with salt and pepper as needed.

If desired, toast the 4 hamburger buns in a dry skillet or toaster for 1 to 2 minutes.

Assemble the sandwiches by spooning the sloppy joe mixture onto the bottom halves of the buns, topping with the other halves, and serving immediately.