Bring a large pot of salted water to a boil and cook pasta according to package instructions. Make sure to save 1 1/4 cups of pasta water!
Add the butter to a saute pan and melt over medium heat.
Add in the minced shallot and garlic and saute for about 3-5 minutes.
Add in the miso and saute for 1 minute.
Whisk in the parmesan, pepper and pasta water.
Whisk until the cheese melts. If you want a super creamy sauce, you can transfer to a blender, but everything should melt together nicely.
Combine with the cooked pasta and toss until the pasta is well coated.
Serve with red pepper flakes for a bit of spice and enjoy!