Start by bringing a large pot of water to a rolling boil over high heat. Generously salt it and add the spaghetti, cooking according to package instructions for 8-10 minutes until al dente. Reserve a cup of starchy pasta water before draining the noodles.

While the pasta is cooking, heat a large skillet over medium heat and add a tablespoon of butter. Once melted, toss in the minced garlic and sauté for 1-2 minutes until fragrant and golden.

Reduce heat slightly and add red chili flakes, cooking for an additional minute. Then, add the remaining butter and vegetarian oyster sauce, stirring for about 2 minutes until combined and bubbly.

Add the drained spaghetti into the skillet and toss vigorously to coat in the sauce. Gradually pour in the reserved pasta water, continuing to toss for another minute.

Taste and season the noodles with salt and pepper. Stir in freshly grated parmesan cheese and garnish with crispy garlic, sesame seeds, and chopped chives or green onions before serving.