Preheat oven to 375°F and prepare a baking dish with olive oil spray. Heat a large pot of water to boiling and add 1/2 tsp salt.

Remove stem and leaves from cauliflower. Cut into small bite sized pieces and place in the boiling water; cook until crisp-tender; about 5 minutes.

Drain well then pat between paper towels to remove all moisture.

In a medium sauce pan bring the cream to a simmer, whisk in the cream cheese and mustard until smooth.

Add the shredded Cheddar, minced garlic, 1/2 tsp salt, white pepper and cayenne pepper whisking until the cheese melts; about 1-2 minutes.

Remove from the heat and stir in the cauliflower.

Pour into the baking dish and top with remaining 1/2 cup of cheese. Bake for 15 minutes until browned and bubbly.