In a medium mixing bowl, combine the thawed spinach, softened cream cheese, shredded mozzarella, Parmesan cheese, garlic powder, onion powder, salt, and pepper. Mix until well blended.
Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
Roll out one puff pastry sheet on a lightly floured surface. Using a sharp knife, shape it into a large triangle, this will be the base of your Christmas tree. Place it on the prepared baking sheet.
Spread the spinach dip evenly over the puff pastry triangle, making sure to get all the way to the edges.
Roll out the second puff pastry sheet and cut it into another large triangle. Carefully place it over the spinach dip-covered triangle. Trim the edges so both layers match up.
Using a sharp knife, cut horizontal slits on both sides of the triangle, leaving the center intact to form the tree trunk. These slits will become the tree branches.
Twist each strip a few times to create a spiral effect, making it look like a real Christmas tree.
In a small bowl, mix the melted butter with the garlic powder. Brush this mixture over the puff pastry for extra golden, buttery goodness.
Bake your Christmas tree puff pastry in the preheated oven for 30-35 minutes, or until the pastry is beautifully golden brown and puffed to perfection. The smell alone will have everyone gathering in the kitchen!
Let the tree cool for about 5 minutes before serving. It’s best enjoyed warm, and you can serve it with a side of marinara sauce for dipping, or just enjoy it as is!