Instant Pot Cauliflower Mac and Cheese

medium/large head cauliflower

whole wheat pasta (elbows, shells, rotini, or similar)

unsalted butter

kosher salt

reduced-fat cream cheese

freshly grated melty, flavorful cheese, such as cheddar, gruyere, provolone, fontina, gouda, or a mix, divided (about 8 ounces; I used half extra-sharp white cheddar and half provolone)

to 12 ounces 2% evaporated milk

garlic powder

black pepper