Bring a pot of water to a boil. Heat oven to 375 degrees F.
Add cauliflower florets to the pot and boil for one minute. Remove with a slotted spoon.
Add pasta shells and follow instructions on the Horizon package except add 1/2 cup milk instead of 1/4 cup.
After draining the macaroni, add cream cheese and cheddar cheese and mix well until combined and cheese is melted. Add cauliflower and mix. Taste and add salt & pepper if needed.
Melt 2 tablespoons butter. In a small bowl, mix together panko breadcrumbs, melted butter, 1/2 teaspoon salt and 1/8 teaspoon pepper.
Spray a ceramic or glass baking dish with cooking spray. Add macaroni and cheese into baking dish. Use a rubber spatula to smooth out the top. Pour breadcrumb mixture over the top.
Bake for 15 to 17 minutes at 375 degrees F, until the breadcrumbs are golden brown.