Heat 2 tablespoons olive oil and 3 sliced garlic cloves in a skillet over medium-high heat. Add a pinch of red pepper flakes, 1 cup white wine and 12 littleneck clams. Cover and cook about 5 minutes. Add 2 pounds mussels and 4 cups Perfect Marinara Sauce. Cook, uncovered, until the mussels open, 4 to 5 minutes. Toss with bucatini and 1/4 cup chopped parsley.
Perfect Marinara Sauce:
Combine 3 tablespoons olive oil, 6 thinly sliced garlic cloves and a pinch of red pepper flakes in a large skillet and cook over medium-low heat until the garlic is golden, about 6 minutes. Crush a 28-ounce can of San Marzano plum tomatoes into the skillet with your hands; rinse the can with about 1 cup water and add to the sauce. Add a handful of torn basil leaves and season with salt. Increase the heat to medium and simmer, uncovered, until thick, 20 to 25 minutes. Toss with 1 pound cooked pasta (makes 4 cups sauce).