In a large pot, bring 4 quarts of salted water to a rolling boil. Add spaghetti and cook according to package directions until al dente, about 8-10 minutes. Reserve 1 cup of pasta water, then drain in a colander.

In a large skillet over medium heat, pour in 2 tablespoons of olive oil. Add minced garlic and red pepper flakes, sautéing for 1-2 minutes until fragrant.

Add the drained spaghetti to the skillet and toss thoroughly to coat the pasta well, adding reserved pasta water as needed.

Remove the skillet from heat, stir in chopped parsley and grated Parmesan cheese. Season with salt and black pepper to taste.

In a medium bowl, combine softened unsalted butter, minced garlic, parsley, Parmesan cheese, garlic powder, and black pepper; mix until smooth.

Slice Italian bread in half lengthwise and spread the garlic butter mixture over each half.

Preheat your oven to 375°F (190°C). Bake the bread halves for 10-12 minutes, or until crispy and golden brown.

Serve spaghetti hot alongside crispy garlic bread. Garnish with extra Parmesan and parsley if desired.