In a large non-stick skillet over medium-high heat, crumble in the pork sausage.  Cook, stirring with a silicone or plastic spoon and breaking up the meat into small pieces, until no pink remains, about 10 minutes.   

Use a slotted spoon to remove the sausage from the skillet and place in a bowl.  Set aside.

Add the scallions and red bell pepper.  Saute until the vegetables are soft.  

Spoon into the bowl with the sausage.

Wipe out the skillet with a paper towel.

Lightly spray the skillet with cooking spray.

Pour in the eggs and cook, gently stirring, constantly until small curds begin to form.  Remove the pan from the heat and allow residual heat to finish cooking the eggs, about 5 minutes.

Season the eggs with salt and pepper.

Assemble the quesadillas.

Preheat the oven to 200 degrees.  

Lay 4 tortillas on a clean surface.  

Top each with sausage, vegetables, and sprinkle with cheese.  Top each with the remaining tortillas.

In a large skillet, use a silicone brush to lightly brush the surface with oil.  Heat the skillet over medium-high heat.

Add a quesadilla and cook until the tortilla is golden and crisp around the edges, about 2 minutes.

Use a spatula to flip the quesadilla and cook the other side, about 2 minutes longer.

Place the quesadilla on a baking sheet and keep warm in the oven.

Repeat with the remaining quesadillas.

Slice each quesadilla into quarters and garnish with chopped parsley or cilantro.  Serve with sour cream, salsa, and guacamole.