Preheat the oven to 300 degrees F.
Bring a large pot of salted water to a boil and cook the pasta to al dente according the package direction.
Combine the beer, half-and-half and cream cheese in a large saucepan over medium-low heat and cook, whisking, until the cream cheese is melted and well incorporated, about 5 minutes.
Add the harissa and mustard powder to the saucepan. Season with salt and pepper and whisk to incorporate. Stir in the Cheddar and smoked gouda and cook, stirring, over low heat until all the cheese is melted.
Add the pasta and toss to combine. Pour into an 8-inch square baking dish. Combine the super-aged gouda, breadcrumbs and oil in a small bowl and sprinkle over the top of the pasta. Bake until golden brown and bubbly, 20 to 25 minutes.
Recipe courtesy of Damaris Phillips