Step 1: Preheat your oven to 375°F (190°C). Lightly grease a medium-sized baking dish (an 8x8 inch or 2-quart dish works well).
Step 2: In a large mixing bowl, combine the softened cream cheese, buffalo sauce, and ranch or blue cheese dressing. Mix well with a spoon or a hand mixer until the mixture is smooth and creamy. Ensure there are no lumps of cream cheese remaining.
Step 3: Stir in the shredded cooked chicken and 3/4 cup of the shredded cheddar cheese and 3/4 cup of the shredded Monterey Jack cheese. Mix until all ingredients are evenly distributed and the chicken is fully coated.
Step 4: Transfer the buffalo chicken dip mixture into the prepared baking dish. Spread it out evenly.
Step 5: Sprinkle the remaining 1/4 cup of cheddar cheese and 1/4 cup of Monterey Jack cheese evenly over the top of the dip.
Step 6: Bake for 20-25 minutes, or until the dip is hot, bubbly around the edges, and the cheese on top is melted and lightly golden brown. If desired, you can place it under the broiler for 1-2 minutes at the end for extra browning, watching carefully to prevent burning.
Step 7: Remove from the oven and let it cool for a few minutes. Garnish with chopped green onions, if using, before serving.
Step 8: Serve hot with tortilla chips, celery sticks, carrot sticks, sliced baguette, or your favorite dippers. Enjoy your delicious homemade buffalo chicken dip recipe!