Zucchini Butter Spaghetti

Ingredients

• 1 1/2 teaspoons kosher salt, plus more for pasta water, and to taste
• 8 ounces (225 grams) spaghetti, cooked al dente
• 1 cup (235 ml) pasta water, reserved
• 1 1/4 pounds (570 grams) zucchini, trimmed, coarsely grated
• 6 tablespoons (85 grams) unsalted butter
• 4 garlic cloves, minced
• 1/4 teaspoon red pepper flakes, or more to taste
• 1/2 cup (45 grams) grated parmesan
• handful fresh basil leaves, cut into thin ribbons