Preheat oven to 350°F. Butter 9×13-inch baking dish.
Place breadcrumbs in small bowl. Drizzle with 2 teaspoons olive oil, and mix well. Set aside.
In large skillet over medium-high heat, warm remaining 1 tablespoon olive oil. Add onion and sauté 3 minutes or until softened. Add diced salami and cook 3 to 5 minutes or until lightly browned. Add spinach and stir until just wilted. Remove from heat and set aside.
Cook pasta in salted water, about 2 minutes short of being fully cooked. Drain cooked pasta, but do not rinse.
Meanwhile, melt butter in medium saucepan over medium-high heat. Whisk in flour. Gradually add milk, whisking continuously, and bring to simmer. Cook 3-5 minutes until thickened. Reduce heat to low, add cheese and red chile flakes.
Add parsley, salami mixture and cooked pasta, and stir until well combined. Pour into prepared baking dish. Sprinkle top evenly with breadcrumbs. Bake 30 to 35 minutes or until top is golden brown and cheese sauce is bubbling around edges.