Creating this Spicy Tuna & Creamy Crab Sushi Bake is a simple process. Follow these steps for a delightful dish:

1. Preheat Your Oven: Set your oven to 375°F (190°C).
2. Cook the Rice: Rinse the sushi rice under cold water until the water runs clear. Combine with 2 ½ cups of water in a pot. Bring to a boil, then reduce heat, cover, and simmer for 18-20 minutes, or until water is absorbed. Remove from heat and let sit for 10 minutes.
3. Prepare the Sauce: In a medium bowl, blend the mayonnaise and softened cream cheese until smooth. Stir in soy sauce, sesame oil, and rice vinegar until well combined.
4. Make the Crab Mixture: In another bowl, combine chopped imitation crab meat with half of the sauce mixture and green onions. Set aside.
5. Prepare the Tuna Mixture: In a separate bowl, mix the spicy tuna with the remaining sauce. Adjust seasonings based on your taste preference.
6. Assemble the Bake: Spread the cooked sushi rice evenly in the bottom of a greased baking dish. Layer the crab mixture over the rice, followed by the spicy tuna mixture.
7. Prepare Panko Topping: In a small bowl, mix panko breadcrumbs with melted butter until evenly coated. Sprinkle this mixture over the top of the dish.
8. Bake in Oven: Place the dish in the preheated oven and bake for 25-30 minutes, or until the top is golden brown and bubbling.
9. Cool and Serve: Once baked, let the dish cool for a few minutes before serving. Optionally drizzle some sriracha on top for an extra kick.

By following these straightforward steps, you’ll have an incredible dish that blends the best of sushi flavors in a warm, comforting bake.