Coat a large griddle with cooking spray and preheat to medium-high.
Arrange 4 tortillas on a flat surface. Top each tortilla with 1/2 cup cheese. Toss salmon with chili powder and place on top of cheese. Top with sliced jalapeno peppers and a second tortilla. Place tortillas on hot griddle and cook 2 to 3 minutes per side, until golden brown and cheese melts.
In a blender, combine avocado, sun-dried tomatoes and lime juice. Process until smooth. Transfer to a bowl, fold in cilantro and season with salt and pepper. Serve quesadillas with guacamole on the side.