Heat olive oil in a large saucepan over medium heat and cook onion until soft and translucent, about 3 minutes. Add garlic and cook 1 more minute. Add rigatoni pasta, coconut milk, diced tomatoes, water, garbanzo beans, red curry paste, curry powder, garlic powder, salt, black pepper, and red pepper; stir to combine. Cover with a tight-fitting lid and bring to a boil. Reduce heat and simmer, stirring every 2 minutes, for 13 to 15 minutes.
Stir in cherry tomatoes and spinach; cook for 2 to 3 more minutes. Taste and adjust seasoning with salt, black pepper, and red pepper.
