Preheat and Prepare: First, preheat your oven to 180°C (160°C fan). Lightly grease a small oven-safe skillet or a 1-litre baking dish.

Create the Creamy Base: In a large mixing bowl, beat the softened cream cheese with a hand mixer or a sturdy spoon until it's completely smooth and free of lumps.

Add Wet Ingredients: Add the sour cream, mayonnaise, and Worcestershire sauce to the bowl. Mix until everything is well combined and the mixture is uniform.

Stir in Seasonings: Add the garlic powder, onion powder, cayenne pepper (if using), and 2 tablespoons of the chopped chives. Give it a good stir.

Fold in the Cheese and Seasoning: Now, fold in about three-quarters of the grated cheddar, all the Parmesan, and 1.5 tablespoons of the everything bagel seasoning. What works best for me is using a spatula to gently fold so you don't overmix. Season with a pinch of salt and a few grinds of black pepper, keeping in mind the seasoning and cheese are already salty.

Assemble the Dip: Spoon the mixture into your prepared baking dish and use the back of the spoon or a spatula to smooth the top into an even layer.

Add the Topping: Sprinkle the remaining grated cheddar cheese evenly over the surface. Then, sprinkle the remaining 1.5 tablespoons of everything bagel seasoning over the cheese.

Bake Until Bubbly: Place the dish in the preheated oven and bake for 20-25 minutes. You'll know it's ready when the cheese is fully melted and the edges are bubbling. For a more golden top, you can switch the oven to grill for the last 1-2 minutes, but watch it carefully to prevent burning.

Rest and Garnish: Carefully remove the dip from the oven and let it rest for at least 5-10 minutes. This is important as it will be extremely hot. Just before serving, garnish with the extra fresh chives.