Preheat the oven to 375°F (190°C).
Slice the Italian bread loaf horizontally in half to create a top and bottom piece.
Place the bread halves cut side up on a baking sheet lined with parchment paper.
Brush the cut sides of both bread halves evenly with olive oil.
Spread the marinara sauce evenly over the cut side of the bottom half of the bread.
Sprinkle the shredded mozzarella cheese evenly over the sauce.
Arrange the pepperoni slices evenly on top of the cheese.
Sprinkle dried oregano and garlic powder evenly over the pepperoni.
Place the top half of the bread over the pepperoni layer, cut side down, gently pressing to secure.
Bake in the preheated oven for 15 to 20 minutes, or until the cheese is melted and bubbly and the bread is toasted.
Remove from the oven and let cool for 5 minutes.
Slice the pizza bread into 6 equal pieces and serve warm.