First things first, make sure your cream cheese is really soft. This is key for a smooth dip. Plop the softened cream cheese into a medium mixing bowl.
Add the sour cream, garlic powder, and a pinch of salt to the bowl with the cream cheese.
Grab a spoon or a rubber spatula and start mixing everything together. Beat it until it's nice and smooth and creamy. No lumps allowed! You can use a hand mixer if you want to make it extra fluffy, but it's totally not necessary.
Now, fold in the shredded cheddar cheese, mozzarella (or Monterey Jack), and the diced pickled jalapeños. Stir everything gently until it's all combined.
At this point, give it a little taste! Do you want a little more salt? A bit more heat? Add a pinch of cayenne or a dash of hot sauce now if you like things spicier.
If you're adding green onions or cilantro, stir most of them in now, reserving a little bit for garnish if you like.
And that's it! You can serve this dip cold right away. Just spoon it into a serving bowl and add any reserved garnish.
Want to bake it? If you prefer a warm, gooey dip, spoon the mixture into a small oven-safe dish (like an 8x8 inch or a small gratin dish). Pop it into a preheated oven at 350°F (175°C) for about 15-20 minutes, or until it's heated through and bubbly around the edges. You can even sprinkle a little extra cheese on top before baking!