Preheat your oven to 375°F (190°C) and butter a 9x13 inch baking dish.
Cook pasta in salted water until just al dente (about 2 minutes less than package instructions). Drain and set aside.
In a large saucepan, melt 4 tablespoons of butter over medium heat. Add flour and whisk constantly for 1 minute to create a roux.
Gradually add warm milk while whisking continuously to prevent lumps. Cook until the sauce thickens, about 5-7 minutes.
Remove from heat and stir in both kinds of cheese, mascarpone, Dijon mustard, cayenne, and garlic powder. Season with salt and pepper.
Fold in the cooked pasta and lobster meat gently until well combined.
Transfer the mixture to your prepared baking dish.
Melt remaining butter and mix with panko breadcrumbs. Sprinkle over the mac and cheese.
Bake for 25-30 minutes until golden brown and bubbling.
Let rest for 5 minutes, garnish with parsley, and serve hot.