Heat the oven to 400 degrees F. Lightly grease a 9 by 13 inch baking dish with olive oil.
Pat the chicken dry and arrange it in the dish in a single layer. Combine the salt, garlic powder, Italian seasoning, onion powder, smoked paprika, black pepper, and red pepper flakes in a small bowl, then rub over both sides of the chicken.
Add the cottage cheese, ¾ cup parmesan, cream cheese, milk, garlic, and salt to a blender. Blend 30 to 60 seconds until completely smooth with no visible curds.
Pour the sauce evenly over the chicken and spread to the edges of the dish.
Scatter the diced tomatoes and chopped spinach over the top, then finish with the remaining parmesan.
Cover tightly with foil and bake 25 to 30 minutes, until the chicken reaches 165 degrees F at the thickest point.
Uncover and broil 2 to 3 minutes for browned, bubbly cheese, if desired.
Rest 5 minutes, finish with fresh herbs and more parmesan, and spoon the sauce over each serving.