Dinner is served!

1 large head cauliflower, stem trimmed and cut vertically into 1″ planks
3 tbsp. extra-virgin olive oil
Kosher salt
Freshly ground black pepper
1 1/2 c. marinara sauce
1/4 c. freshly grated Parmesan, divided
1 shredded mozzarella cheese
1/4 c. basil leaves, torn if large
Crushed red pepper flakes