In a large mixing bowl, combine warm water, sugar, and active dry yeast. Let sit for 5–10 minutes until bubbly and frothy.

Add flour, salt, and olive oil to the yeast mixture, mixing until a dough forms.

Knead the dough on a floured surface for 8–10 minutes until smooth and elastic.

Place dough in a greased bowl, cover, and let rise in a warm spot for about 1 hour.

Heat olive oil in a skillet over medium heat. Add minced garlic and sauté until fragrant.

Stir in the fresh spinach and cook until wilted.

Remove from heat and fold in the caramelized onions. Season with salt and pepper, then let cool.

Once the dough has risen, punch it down and roll it out into a rectangle about 1/4 inch thick.

Spread marinara sauce over the dough, leaving a small border.

Distribute the spinach and onion filling over the sauce evenly.

Roll the dough tightly from one long side into a log and slice into 1–1.5 inch thick rolls.

Preheat oven to 350°F (175°C) and allow sliced rolls to rest in a greased baking dish for 30 minutes.

Bake rolls for 25–30 minutes or until golden brown and dough sounds hollow when tapped.

Allow the rolls to cool for about 5–10 minutes before serving.

Serve warm or at room temperature, best with extra marinara sauce for dipping.