Chop the turkey sausage into bite-size pieces and set aside.
Crack the eggs into a large bowl or measuring cup with a pour spout to make it easier to pour the eggs into the muffin tins. Whisk the eggs to scramble them. Rough chop the spinach and add into the eggs along with the shredded cheese, salt, and pepper. Whisk once more to combine.
Grease a nonstick muffin tin with butter or spray, and then place the biscuits into the muffin tins. Use your fingers to mold the biscuits to the muffin tins, working your way up to create a biscuit cup.
Pour the egg mixture into the muffin tins lined with the biscuits. Fill about 1/3 of the way. Top the muffin cups with the chopped turkey sausage.
Bake the breakfast muffins for 20 minutes, or until the eggs are completely cooked. Top the muffins with more of the shredded cheddar cheese and then place in the oven for 1-2 minutes to allow it to melt.
Serve as desired.
Notes
Make sure you use a nonstick muffin tin to prevent sticking.
If you don't like spinach you can also use kale, or leave the greens out.