Preheat Oven: Start by preheating your oven to 375°F (190°C).

Mix Base Ingredients: In a large mixing bowl, combine the softened cream cheese, mayonnaise, shredded cheddar and mozzarella cheese, and diced green onions. Stir until well blended.

Add Jalapeños: Gently fold in the diced jalapeño peppers. Adjust the amount based on your preferred spice level.

Prepare Baking Dish: Transfer the mixture to an oven-safe baking dish, spreading it evenly.

Create Topping: In a separate bowl, combine the Panko bread crumbs, grated Parmesan cheese, and melted butter. Mix until the crumbs are well-coated.

Top the Dip: Sprinkle the breadcrumb mixture evenly over the top of the dip.

Bake: Place the dish in the preheated oven and bake for about 20-25 minutes or until the top is golden brown and the dip is bubbling around the edges.

Garnish and Serve: Once out of the oven, let the dip cool for a few minutes. Garnish with chopped fresh parsley if desired and serve warm with your favorite chips or veggies.