Start by preheating your oven to 350°F (175°C). Grease a 9x13 inch casserole dish with a light coat of olive oil.
In a large mixing bowl, combine the softened cream cheese, shredded chicken, sharp cheddar cheese, diced jalapeños, and sour cream. Mix vigorously until smooth.
Add the garlic powder, onion powder, smoked paprika, and a pinch of salt and black pepper. Stir thoroughly until evenly incorporated.
Transfer the chicken mixture into the prepared casserole dish, spreading it evenly across the bottom.
In a separate bowl, combine the panko breadcrumbs with a drizzle of olive oil, mixing until lightly coated. Sprinkle over the top of the casserole.
If desired, scatter the diced tomatoes on top of the breadcrumbs.
Place the casserole in the preheated oven and bake for 25-30 minutes, or until the top is bubbling and golden brown.
Once cooked, allow to cool for a few minutes and garnish with sliced green onions before serving.
Notes
Serve with a dollop of sour cream for added richness.