Preheat the oven to 375°F. Grease two mini-muffin pans with nonstick cooking spray.
In a large pot of boiling salted water, cook the pasta al dente according to package instructions, about 7-9 minutes. Drain and set aside to cool.
In a large saucepan over medium heat, melt the butter. Add the flour, garlic powder and mustard powder into the pot and stir to combine, about 2 minutes. Add the milk, season with salt and pepper, and whisk well to combine. Bring the mixture to a simmer over medium-low heat, stirring occasionally for 5 minutes.
Remove the pot from the heat and stir in Grand Cru. Stir until the mixture is melted. Fold in the cooked pasta and mix until it is evenly coated with the sauce.
Scoop about 2 tablespoons of the mac-and-cheese mixture into each muffin cup. Pack the mac and cheese into the muffin cups with the back of a spoon. Sprinkle panko breadcrumbs and remaining cheese on top. Yields 36.
Bake in the preheated oven until the cheese is melted and the breadcrumbs become golden, 20 to 25 minutes.
Allow the bites to cool for 5-10 minutes before removing from the muffin cups and serving.