You can make this more interesting any number of ways: adding chopped broccoli, cauliflower or kale to the boiling pasta in the last 3 minutes of cooking. Adding a little paprika or garlic to the cheese mixture. Lemon zest at the end. But I also think it’s fine to let this be what it is: a really, extremely, very simple and easy way to make a classic macaroni and cheese that tastes very close to the box, as fast as possible.
1. Cook pasta in a pot of salted boiling water until cooked through. Save one cup pasta water and drain the pasta. Return the pasta back to the pot along with cream cheese, parmesan and half the pasta water.
2. Bring to a simmer, reduce the heat to medium and stir to melt the cheeses. Continue to cook, stirring occasionally, until the sauce is thickened and the pasta is all evenly coated, 3 to 5 minutes. If this happens faster than you anticipated and it’s a bit thick, add more of that pasta water. Add pepper if it’s for you or your child might enjoy black pepper.
3. Let cool enough for the baby (or you) to eat before serving.
DO AHEAD: Because there will probably be leftovers, of course this can be made ahead. Give the pasta a splash of water before reheating stovetop or in the microwave.