Bring a large saucepan of salted water to the boil, add pasta and cook to al dente (according to package directions).
225 g dried pasta
When the pasta has finished cooking, drain and reserve 1 cup of the pasta cooking water (you might not need it all).
Meanwhile, heat unsalted butter in a frypan over medium heat.
4½ tablespoon unsalted butter
When the butter starts to foam, mix in miso paste and garlic and fry for 30 seconds.
1½ tablespoon white miso paste, 2 garlic cloves
Add reserved pasta water (start with ½ cup pasta water, adding more as needed) to the butter mixture in the pan and whisk together over low heat until combined and uniform with no lumps.
Add drained pasta to the liquid in the pan and stir to allow the pasta to absorb most of the liquid until only about a few tablespoons remain.
Finally, sprinkle in grated parmesan over low heat and keep mixing to melt the parmesan and create a silky sauce (adding a little more reserved pasta water if needed). Add confit cherry tomatoes now to heat through if using.
½ cup freshly grated parmesan, confit cherry tomatoes
Serve pasta immediately in bowls, garnished with extra parmesan cheese and ground black pepper.