Prepare the pizza dough according to instructions and let rise in a warm place for about 1 hour.

In a large skillet over low heat, add olive oil and sliced onions; caramelize for 20-30 minutes.

Add minced garlic to the skillet and sauté for 1 minute, then fold in spinach and cook until wilted.

Roll out dough on a floured surface to 1/4 inch thick and cut into rectangles.

Spread marinara sauce on each rectangle, add filling, then roll tightly and place seam-side down in a baking dish.

Let the rolls rise for another 30 minutes.

Preheat oven to 350°F (175°C) and bake for 20-25 minutes until golden brown.

Let cool slightly, then serve warm with extra marinara sauce on the side.