Cook spaghetti to package directions and drain. (Time-saver tip: grate the mizithra while waiting on the pasta to cook).
Leave the pasta in the colander and return the pot to the stove.
Melt the butter over medium heat, shaking the pan every so often as the butter continues to cook.
Once the butter reaches a golden/medium-brown color, remove from heat.
Add the pasta to the pot and toss to coat with the butter. Alternately, you can add the pasta to a serving dish and add the butter to it there. Just be sure to grab a rubber spatula to get all that butter!
Add most of the cheese and toss to coat, reserving a small amount to top each plate with.