Bring a large pot of salted water to a boil. Once boiling, cover and keep on a low heat.
In a large saucepan, heat olive oil oven over medium-high heat. Add the bacon and cook it until it's nice and crispy (about 9-10 minutes). Remove from the heat.
In a mixing bowl, whisk the miso, chili garlic sauce, and some water from the pot until you get a nice smooth consistency.
Add in the egg and whisk until fully incorporated. Set aside.
In the post, cook the pasta and drain 1 minute before the time indicated on the package instructions. Reserve about 1/2 cup of pasta water.
Add the pasta to the saucepan with the bacon, over medium high heat. Once everything is really hot, remove the pan from the heat and pour in the miso/egg mixture. Give it a quick mix and slide it out of the pan before the eggs start to scramble.
Add in the cheese and pasta water until you like the consistency.
Add salt and pepper to taste, garnish with scallions, and serve.