Preheat oven to 375 degrees. Bring pot of water to a boil, season with salt. Spray an 8x8 dish with vegetable oil. Cook the cauliflower in the boiling water until crisp-tender, about 5 minutes. Drain well & pat dry with paper towel. Transfer the cauliflower to baking dish & set aside.
Bring the cream to a simmer in a pan then add the cream cheese with a whisk along with the mustard. Whisk till smooth. Stir in the cheese, salt & pepper, garlic powder & whisk until cheese melts, about 2 minutes. Remove & poor over the cauliflower, stir all to combine.
Top with the remaining cheese ( use what amt. you like) Bake until browned & bubbly hot. About 15-20 minutes. Cool a few minutes before serving. ENJOY!!