Cook the egg noodles according to package instructions. Drain and set aside.
In a large skillet, cook the chopped bacon over medium heat until crispy. Remove the bacon and set aside, leaving the bacon grease in the skillet.
Add the diced onion to the skillet and sauté in the bacon grease for about 3-4 minutes until translucent. Add the minced garlic and cook for an additional 1 minute.
Stir in the chopped cabbage, salt, black pepper, and red pepper flakes (if using). Cook for about 10-12 minutes, stirring occasionally, until the cabbage is tender.
Add the cooked egg noodles, soy sauce, olive oil, and apple cider vinegar to the skillet. Toss everything together and cook for another 2-3 minutes to heat through.
Stir in the crispy bacon and mix well. Remove from heat and garnish with chopped green onions if desired.