Preheat the oven to 400 degrees F.
Butter a 9x13 casserole dish and set aside.
Grate zucchini on the large holes and transfer to a colander placed over the sink. Sprinkle with 1 teaspoon salt and stir. Let stand for 15 min, then squeeze out the excess moisture with your hands. Transfer drained zucchini to a large mixing bowl.
In a small bowl mix sour cream, lemon juice, and 1/2 teaspoon baking powder.
Stir in the eggs and sour cream mixture into the shredded zucchini.
Add cooked shirataki rice, 1 cup of cheddar cheese, and 1 cup of mexican cheese.
Stir in the green onions, remaining 1/2 teaspoon salt, minced garlic, paprika and onion powder.
Pour mixture into the prepared casserole dish, spread the yogurt over the top. Bake uncovered for 20 minutes.
Sprinkle remaining 1 cup of mozzarella cheese and cheddar cheese on top and bake uncovered on the center rack in the preheated oven for 20-30 minutes.
Let stand for 10 minutes before serving.
Garnish with sour cream, chopped tomatoes, green onions, and serve.