Make the dough: In a small bowl, combine warm water, sugar, and yeast. Let sit for 5–10 minutes until foamy. In a large mixing bowl, whisk together flour and salt. Add yeast mixture and olive oil. Stir until dough forms, then knead on a floured surface for 5–7 minutes until smooth. Place in a lightly oiled bowl, cover, and let rise for 1 hour or until doubled.

Preheat the oven: Place a pizza stone in the oven if you have one, and preheat to 475°F (245°C) for at least 30 minutes. If using a baking sheet, lightly grease it.

Prepare the spinach: Heat 1 tablespoon olive oil in a skillet over medium heat. Add garlic and sauté for 30 seconds. Stir in spinach and cook until just wilted, about 2 minutes. Remove from heat and set aside.

Shape the dough: Punch down the dough and roll it out on a floured surface into a 12-inch circle. Transfer to parchment paper (if using a stone) or directly onto a greased baking sheet.

Assemble the pizza: Brush the crust with 1 tablespoon olive oil. Evenly spread the sautéed spinach and garlic over the dough. Top with mozzarella, feta, and red onion slices. Sprinkle with oregano and crushed red pepper flakes, if using.

Bake: Transfer the pizza to the oven and bake for 12–15 minutes, or until the crust is golden and the cheese is melted and bubbly.

Serve: Remove from oven and let rest for 5 minutes. Slice and serve warm, with lemon wedges on the side if desired.