Cook the elbow macaroni in your Instant Pot using the "Sauté" function according to package instructions until al dente. Drain and set aside.
In the Instant Pot, melt the butter (or vegan butter) using the "Sauté" function. Stir in the cornstarch (or arrowroot powder) until well combined to create a roux.
Gradually whisk in the milk of your choice. Continue whisking until the mixture thickens, about 5-7 minutes.
Reduce the heat by switching off the "Sauté" function, then add the shredded cheddar and mozzarella cheese (or vegan alternatives), stirring until the cheese melts and the sauce is smooth. Season with salt, black pepper, and paprika.
Combine the cooked macaroni and the cheese sauce in the Instant Pot. Mix well.
In a small bowl, combine the breadcrumbs with the grated Parmesan (or vegan Parmesan). Sprinkle this mixture evenly over the macaroni.
Set your Instant Pot to "Keep Warm" mode, cover with a glass lid (or use the Instant Pot lid without sealing), and let it sit for about 10-15 minutes to allow the top to become crispy.
Enjoy your Baked Mac and Cheese in the style that suits you best, whether it's baked in the oven, air fried, slow-cooked, or prepared in an Instant Pot. It's a versatile and satisfying dish for all mac and cheese lovers!