1) Scramble eggs and grease each muffin tin with a bit of butter.
2) Add baby spinach to each tin. Just a few leaves per tin will do the trick.
3) Evenly divide eggs between 12 muffin tins.
4) Bake eggs at 350 degrees for 20-22 minutes until they are cooked through.
5) Pop the eggs out of the tins.
6) To make a sandwich, toast the english muffin, add the cheese and egg. Mash the egg down a bit so it evenly covers the muffin.
7) Bake for a few minutes to melt the cheese.
8) These freeze great. You can either freeze the egg cups without muffins or make the sandwiches and then wrap them in foil and freeze them as completed sandwiches.
9) The individual egg cups reheat perfectly in the microwave. The foil-wrapped sandwiches reheat better in the oven for 30 minutes at 350 degrees (keep them wrapped in the foil).