Spray four ramekins with cooking spray and set aside.
In a small bowl, whisk together eggs, milk, salt, and pepper. Pour evenly into four ramekins. Wrap ramekins tightly in foil.
Pour 1 1/2 cups water into Instant Pot®.
Place foil-wrapped ramekins into Instant Pot®, stacked two by two. Close lid and set pressure release to Sealing.
Press Manual or Pressure Cook button and adjust time to 8 minutes.
While eggs are cooking, toast English muffins and spread with butter.
When the timer beeps, let pressure release naturally for 2 minutes and then quick release the remaining pressure. Unlock lid and remove it.
Carefully remove ramekins from Instant Pot®. Pour out water from cooking pot and put cooking pot back into Instant Pot®.
Press Sauté button and place sausage patties inside Instant Pot®. Heat sausage patties, turning once, 1 minute. Remove from Instant Pot®.
Remove each egg from its ramekin and place on one half of English muffin. Top each egg with a sausage patty and a slice of cheese. Place other half of the English muffin on top to create a sandwich.