Step 1: Preheat and Prepare
Preheat your oven to 375°F (190°C). Lightly grease a 9×13 inch (23x33cm) baking dish with butter, cooking spray, or a thin layer of oil. This is critical to prevent sticking and ensure easy serving.

Step 2: Create the Luxurious Buffalo Chicken Filling
In a large mixing bowl, combine the softened cream cheese and 1/2 cup of ranch or blue cheese dressing. Use a hand mixer or a sturdy spatula to beat them together until completely smooth and creamy. This is the base of your sauce. To this cream base, add the melted 1/4 cup butter, Buffalo hot sauce, minced garlic, smoked paprika, black pepper, and celery seed (if using). Mix until fully incorporated. Now, fold in the shredded chicken, diced celery, most of the shredded mozzarella (reserve a small handful for topping), all of the blue cheese or cheddar crumbles, and about two-thirds of your sliced green onions. Stir gently until every piece of chicken is uniformly coated in the glorious, creamy, spicy sauce. Taste and adjust seasoning—remember, the crescent rolls are mild, so the filling should be robust.

Step 3: Assemble the First Layer
Unroll one can of the crescent roll dough. Do not separate the triangles. Instead, press the perforated seams together firmly to create one solid rectangle of dough. Carefully place this rectangle into the bottom of your prepared baking dish, pressing it gently to fit and reach the edges. This forms a delicious, flaky bottom crust that will soak up the flavorful juices.

Step 4: Add the Filling and Top It Off
Spread the entire bowl of Buffalo chicken filling evenly over the crescent roll dough layer in the baking dish. Use your spatula to create a smooth, even surface. Now, unroll the second can of crescent roll dough, again sealing the perforations to form a rectangle. Carefully place this second sheet of dough over the chicken filling, stretching it lightly if needed to cover the surface. It’s okay if it doesn’t seal perfectly at the edges; it will expand and bake together.

Step 5: Create the Golden, Flaky Finish
Using a pastry brush, generously brush the 2 tablespoons of melted butter all over the top layer of crescent dough. This will promote an even, deep golden-brown, and beautifully crisp crust. If desired, sprinkle the optional everything bagel seasoning or garlic powder evenly over the buttered top.

Step 6: Bake to Perfection
Place the assembled casserole in the preheated oven. Bake for 25 to 30 minutes. The casserole is done when the top crescent roll layer is puffed and a deep, golden brown, and the filling is visibly bubbling around the edges. For extra assurance, an instant-read thermometer inserted into the center of the chicken filling should read at least 165°F (74°C).

Step 7: Garnish and Serve
Remove the casserole from the oven and let it rest for 5-10 minutes. This rest is crucial—it allows the bubbling filling to settle slightly, making it easier to cut and serve without it gushing out. Just before serving, garnish with the remaining sliced green onions, the chopped fresh parsley, and if you like, a light drizzle of additional ranch or blue cheese dressing. Slice into squares and serve immediately.