How to Make It
Heat a large heavy-bottomed skillet over medium. Add beef, and cook, stirring often, until browned, about 6 minutes. Transfer beef to a plate lined with a paper towel; discard remaining grease, and wipe skillet clean.
Add bacon to skillet over medium, and cook, turning occasionally, until sides are crisp, but centers are still pliable, about 8 minutes. Transfer bacon to a cutting board, and roughly chop bacon. Reserve 1 tablespoon of bacon drippings in skillet; discard remaining drippings.
Add onion to skillet, and cook, stirring often, until translucent, about 5 minutes. Add garlic and cook, stirring often, until fragrant, about 1 minute. Return beef and chopped bacon to skillet. Add ketchup and tomato paste, stirring to loosen any browned bits from bottom of skillet. Stir in tomato sauce, brown sugar, Worcestershire, vinegar, salt, pepper, and sage. Reduce heat to medium-low, and simmer, stirring occasionally, 20 minutes.
Meanwhile, bring a large pot of salted water to a boil over high. Add spaghetti, and cook until al dente, 11 to 13 minutes. Drain pasta.
Melt butter in a medium nonstick skillet over medium. Add panko, and cook, stirring often, until panko is golden, about 4 minutes; stir in parsley. Serve meat sauce over spaghetti, and sprinkle with toasted panko.