Prepare the Filling

1. Preheat the Oven: Preheat your oven to 375°F (190°C). Lightly grease a baking sheet with olive oil or line it with parchment paper for easy cleanup.
2. Sauté the Spinach: In a large skillet, heat a tablespoon of olive oil over medium heat. Add the chopped spinach and cook for 2-3 minutes until wilted. Remove from heat and set aside.
3. Mix the Filling: In a medium mixing bowl, combine the cream cheese, sour cream, Parmesan cheese, mozzarella, garlic powder, onion powder, and salt and pepper. Stir until well combined. Add the sautéed spinach and chopped artichokes and mix until evenly distributed.

Assemble the Squares

1. Roll Out the Puff Pastry: Unroll the puff pastry sheet on a lightly floured surface. Gently roll it out to smooth any creases, making it slightly larger than its original size.
2. Add the Filling: Spread the spinach and artichoke mixture evenly across the puff pastry, leaving a small border around the edges.
3. Fold and Cut: Carefully fold the edges of the pastry over the filling to create a rectangular shape. Then, using a sharp knife or pizza cutter, slice the pastry into squares or rectangles, depending on your preferred size.

Bake

1. Bake the Squares: Place the pastry squares onto the prepared baking sheet and bake for 25-30 minutes, or until the pastry is golden brown and crispy.
2. Cool Slightly: Let the squares cool for a few minutes before serving. The filling will be hot, so give them a little time to set before taking that first bite.