Heat the olive oil in a large, deep skillet over medium-high heat. Is your pan hot enough? The oil should shimmer slightly but not smoke.
Add the ground beef and break it apart with a wooden spoon. Season with a good pinch of salt and black pepper. Brown the meat until no pink remains – about 5-7 minutes. Don't stir constantly! Let it develop some brown bits for maximum flavor.
Add the holy trinity – onions, carrots, and celery. Cook until the vegetables soften, about 5 minutes. Then add the garlic and cook for another 30 seconds until fragrant. Your kitchen should smell amazing at this point!
Stir in the tomato paste and cook for 2 minutes, letting it caramelize slightly. This little step adds a massive depth of flavor – don't skip it!
Pour in the red wine and use your wooden spoon to scrape up all those delicious browned bits from the bottom of the pan. Let the wine reduce by half, about 3-4 minutes. Yes, the alcohol cooks off, so it's safe for the kiddos!
Add the crushed tomatoes, bay leaves, oregano, thyme, and red pepper flakes (if using). Stir well, then reduce heat to medium-low and simmer uncovered for 20-25 minutes, stirring occasionally. The sauce should thicken slightly.
Meanwhile, cook the spaghetti in a large pot of salted water according to package directions until al dente. Remember: the pasta should still have a slight bite!
When the sauce has thickened, stir in the balsamic vinegar and taste for seasoning. Add more salt and pepper if needed.
Drain the pasta but save about 1/2 cup of the starchy pasta water. Add the drained pasta directly to the sauce along with a splash of the pasta water and the grated Parmesan cheese. Toss everything together until the pasta is coated evenly.
Serve immediately, topped with more freshly grated Parmesan and a sprinkle of chopped basil. Prepare for the compliments!