In a skillet, cook the ground turkey on medium heat until no pink remains. Add salsa and corn and cook until heated.
Spray a 2 quart round casserole dish with nonstick spray. Spoon one cup meat mixture into bottom of dish. Cover with 3 tortillas, overlapping if necessary to fit in dish, and cover with meat and half the shredded cheese. Repeat, leaving the top layer as meat and cheese.
Cover and bake 20 to 25 minutes, or until heated through. Uncover and bake an additional 5 to 10 minutes until cheese is brown and bubbly.
Allow to set for 5 minutes, cut into wedges. Serve with a scoop of sour cream and jalapeño slices, if desired.