In a large bowl, combine the warm water, sugar, and yeast. Let it sit for 5-7 minutes until frothy and activated.
When the yeast is ready, add the olive oil, salt, and gradually mix in the flour until a soft dough forms.
Turn the dough onto a floured surface and knead for 5 minutes until smooth and elastic. The perfect dough should spring back when lightly pressed with your finger.
Place in an oiled bowl, cover with a damp cloth, and let rest in a warm spot for 15-20 minutes.
While the dough rests, mix the marinara sauce with Italian seasoning in a small bowl. In a separate bowl, combine the mozzarella and parmesan cheeses.
Preheat your oven to 375°F (190°C). Roll the dough into a rectangle approximately 12×16 inches on a floured surface.
Spread the marinara mixture evenly across the dough, leaving a ½-inch border around the edges. Sprinkle with the cheese mixture, then distribute the vegetables and pepperoni evenly over the surface.
Starting from the long edge, tightly roll the dough into a log shape, pinching the seam to seal.
Use a serrated knife to gently cut the log into 12 equal pieces, each about 1½ inches thick. For cleaner cuts, chill the rolled log for 10 minutes before slicing.
Place the rolls cut-side up in a greased muffin tin or on a parchment-lined baking sheet. Brush the tops with beaten egg for a golden shine.
Bake for 15-18 minutes until the rolls are puffed and golden brown, and the cheese is bubbly. The internal temperature should reach 190°F for perfectly baked rolls.
Mix melted butter with garlic powder and brush over the hot rolls. Sprinkle with fresh parsley for a burst of color and flavor.