Preheat your oven to 400°F (200°C).

In a mixing bowl, combine the chopped spinach, mozzarella cheese, ricotta cheese, Parmesan cheese, minced garlic, Italian seasoning, salt, and pepper.

On a lightly floured surface, roll out the pizza dough into a rectangle about 1/4 inch thick.

Spread the spinach filling evenly over the rolled-out dough, leaving about an inch of space around the edges.

Starting from one long edge, carefully roll the dough tightly into a log.

Pinch the ends of the dough to seal them shut.

Place the rolled Stromboli seam side down on a baking sheet lined with parchment paper.

Brush the top with the beaten egg.

Bake in the preheated oven for 25-30 minutes or until golden brown.