Butter a large casserole dish with 1 tablespoon of the butter and set aside.
Bring a large pot of salted water to a boil. Add the macaroni and cook until al dente, about 10 minutes. Drain in a colander and rinse under cold running water. Drain well.
In a large skillet over medium-high heat, cook the sausage, stirring, until browned and the fat is rendered. Remove with a slotted spoon and drain on paper towels. Pour off all but 1 tablespoon of fat from the pan. Add the onions, bell peppers, and 1 teaspoon of the Essence, and cook, stirring, over medium-high heat until soft, about 3 minutes. Add the garlic and anise seeds, and cook, stirring, for 1 minute. Remove from the heat.
Melt the remaining stick of butter in a large, heavy saucepan over medium heat. Add the flour, and stirring constantly with a wooden spoon, cook over medium heat until thick, 3 to 4 minutes, being careful not to let the flour brown. Using a whisk, add the milk in a steady stream and cook, whisking constantly, until thick and smooth, 4 to 5 minutes. Remove from the heat. Add the salt, pepper, cayenne, and 2 cups of the cheese, and stir well. Add the noodles, cooked sausage and vegetables, and stir well to combine. Pour into the prepared baking dish.
In a mixing bowl, combine the remaining 1 cup of cheese with the breadcrumbs and remaining 2 teaspoons of Essence. Sprinkle over the macaroni and bake until golden brown and bubbly, about 25 minutes.
Remove from the oven and let rest for 5 minutes before serving.
Essence (Emeril's Creole Seasoning):
Yield:about 2/3 cup
Combine all ingredients thoroughly and store in an airtight jar or container.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch. Published by William and Morrow, 1993.