Wash the fresh spinach thoroughly under cool running water. Drain it well and remove any thick stems. Roughly chop the leaves into smaller pieces for easier mixing.

Heat olive oil in a skillet over medium heat. Add the chopped onion and cook until soft. Add the spinach and cook until wilted. Remove excess moisture before continuing.

Place softened cream cheese in a large mixing bowl. Letting it soften first makes mixing easier. Stir until smooth and creamy before adding the other ingredients.

Add sour cream and mayonnaise to the cream cheese. Stir well until the mixture becomes smooth. Make sure there are no large cream cheese lumps remaining.

Stir in mozzarella, Parmesan, minced garlic, salt, black pepper, and garlic powder. Mix gently until all ingredients are evenly distributed throughout the creamy mixture.

Add the cooked spinach and softened onion mixture to the bowl. Stir everything together until the spinach is spread evenly. Make sure there are no large clumps.

Spoon the spinach mixture into a small baking dish. Spread the top evenly with a spatula. Sprinkle a little extra mozzarella over the surface if desired.

Preheat your oven to 375°F. Bake the spinach dip for about 18 to 20 minutes. The edges should be bubbling, and the cheese should look melted and lightly golden.

Remove the hot dip from the oven and let it rest for five minutes. This helps the texture settle slightly. Serve warm with bread, crackers, chips, or fresh vegetables.