Cook the bacon in a cast iron skillet. Remove and drain on paper towel before crumbling.
Add the minced garlic to the bacon grease and cook until fragrant (about thirty seconds). Remove from heat.
Cook the pasta in boiling, salted water. Drain and immediately place back in the pot with the bacon, bacon grease and garlic. Place pot back on the stove over low heat, add the beaten egg and whisk continuously for three minutes, or until the egg cooks and thickens, creating a silky sauce over the noodles. Be careful not to stop whisking or the egg will scramble!
Season with salt and pepper and serve immediately.