Bring a large pot of generously salted water to a rolling boil. Add the bucatini and cook according to package directions until al dente, about 9-11 minutes. Reserve 250ml of pasta water before draining.

While the pasta cooks, heat the olive oil and 2 tablespoons of vegan butter in a large deep skillet over medium-high heat. Add the asparagus pieces and sauté for 3-4 minutes until bright green and tender-crisp. Season with salt and transfer to a plate.

Reduce heat to medium and add the remaining 4 tablespoons of vegan butter to the same skillet. Once melted, add the sliced garlic and red pepper flakes, cooking for 1 minute until fragrant but not browned.

Pour in the white wine and let it simmer for 2-3 minutes until reduced by half, scraping up any bits from the bottom of the pan.

Add the lemon juice and zest to the skillet, stirring to combine. Toss in the drained bucatini and asparagus, adding pasta water gradually while tossing until a silky sauce coats the pasta.

Remove from heat and stir in the nutritional yeast and half the parsley. Season generously with salt and black pepper to taste.

Divide among warm serving bowls and garnish with remaining fresh parsley, extra lemon zest, and a drizzle of olive oil. Serve immediately.