Heat the olive oil in a large pot (5-quart) over medium to low heat. Add the diced onions, stirring often, until the onions are translucent, about 5 minutes.
Add the sausage and garlic, red pepper flakes, and fennel. Cook until sausage is no longer pink, about 2 minutes. Drain oil.
Increase the heat to medium high. Pour in the wine and bring to a boil until it has reduced to about 3 tablespoons, approximately 5 minutes.
Stir in the Classico(R) Tomato & Basil sauce and bring to a quick boil. Add the clams, cover, and cook until clam shells open, 8 to 10 minutes. Check often to avoid overcooking.
Preheat oven to 375 degrees F (190 degrees C).
Mix together remaining 2 tablespoons olive oil, 2 cloves minced garlic, salt, and cracked pepper. Brush mixture on both sides of the baguette slices. Arrange slices on a baking sheet.
Bake until its golden brown, 8 to 10 minutes.
Ladle the clams and sauce into bowls; top with fresh parsley and shaved parmesan cheese. Serve with the crostini.