Preheat a skillet over medium heat and add the olive oil.
Cook the turkey sausage patties in the skillet for 4-5 minutes on each side or until fully cooked and browned. Remove from skillet and set aside.
Slice the ciabatta rolls horizontally and toast them lightly in the same skillet or a toaster until golden brown. Set aside.
In a medium bowl, whisk together the eggs, whole milk, salt, and black pepper until well combined.
Heat the butter in a non-stick skillet over medium-low heat. Pour in the egg mixture and cook gently, stirring occasionally, until the eggs are softly scrambled and cooked through, about 4-5 minutes.
To assemble each sandwich, place two turkey sausage patties on the bottom half of each toasted ciabatta roll.
Top the sausage patties with half of the scrambled eggs, then place two slices of cheddar cheese over the eggs.
Add half a cup of fresh spinach leaves on top of the cheese.
Cover with the top half of the ciabatta roll and press gently.
Serve the breakfast sandwiches warm.