Cook spaghetti to al dente according to pasta package instructions. Reserve about ¼ cup of pasta cooking water. Drain pasta and set aside.
Place bacon in a single layer in a large cold pan. Set over low heat and slowly cook bacon to render fat. Once bacon has released some grease, increase to medium heat.
Flip bacon pieces are needed for even cooking. Continue to cook based on your desired of crispiness. Remove from heat and remove bacon pieces and allow to drain on a paper towel lined plate. Keep rendered bacon fat in skillet.
In a medium bowl, whisk eggs, grated cheese, salt, pepper, and 2 tablespoons of reserved pasta water until smooth. Set aside.
Heat skillet with bacon fat over medium heat. Once hot, add minced garlic. Stir and cook until fragrant and lightly browned, about 45-60 seconds. Add cooked pasta and bacon. Toss to combine.
Pour in egg mixture. Quickly toss to coat pasta in sauce while the heat is still on, about 30-40 seconds. At this point, the "sauce" should have thickened. Remove from heat.
If sauce is too thick, add in splash of reserved pasta water. Season with additional cheese and black pepper, as desired. Serve immediately.