Lightly spray a Dutch oven with vegetable cooking spray and heat over medium high heat. Add ground turkey and cook until no longer pink in the middle, about 7-8 minutes. Stir often to crumble and separate the turkey.
Pour cooked turkey into a strainer and run under hot water to remove excess fat, drain well.
Wipe Dutch oven clean of grease with a paper towel.
Preheat oven to 350 degrees F.
Place 8 tortilla halves onto the bottom of the Dutch oven, overlapping, so they cover the entire bottom.
Next, layer in the following order: half of the tomatoes, half of the zucchini, half of the cooked turkey, sprinkle 1 teaspoon of chili powder evenly over the meat, layer half of the ricotta cheese evenly, half the olives, 1/3 of the enchilada sauce, and 1/2 cup of Monterey Jack cheese.
Repeat the layer starting again with the tortillas.
Top with a final layer of tortillas, remaining 1/3 of enchilada sauce, and remaining 1/2 cup Monterey Jack cheese.