Preheat oven to 350º F and lightly grease a 9x13-inch baking dish. Bring a large pot of salted water to boil and cook macaroni according to package directions, or until al dente. Add broccoli to the boiling water for the last 3-4 minutes of cooking. Drain and set aside. Melt butter in a large saucepan over medium-high heat. Stir in flour to create a smooth and thick roux, then add garlic and onion powder, garlic salt and pepper. While stirring continuously, slowly pour in evaporated milk and heavy cream.
Bring mixture to a boil and cook until thickened, then remove from heat and stir in cheese. Taste and adjust seasoning, if necessary. Pour 1/2 of pasta and broccoli into casserole dish and cover with 1/2 of cheese sauce. Repeat with remaining pasta and sauce, making sure to evenly coat all pasta. Top with Parmesan cheese, pine nuts, and breadcrumbs, place in oven and bake for about 30 minutes, or until sauce is bubbly and pine nuts toasted.
Optional: make your own breadcrumbs by tearing up 1/3 loaf of crust bread into small pieces. Drizzle with butter, salt and pepper, and place under the broiler for 3-5 minutes, tossing in between, or until evenly toasted.