Line a rimmed baking sheet with parchment paper and arrange the tomatoes in a single layer on it. Drizzle with oil and season with salt and pepper. Bake until the tomatoes have decreased in size and look slightly dry, 1 to 1 1/2 hours.
Raise the oven temperature to 350 degrees F. Grease a bundt pan with cooking spray.
Arrange the dough in the prepared pan so the ends touch each other, then pinch the ends together so the dough makes one large ring. Using a knife, make a few slices in the top of the dough. Bake until the bread is golden brown and the internal temperature reaches 200 degrees F, 25 to 30 minutes. Let cool 5 minutes, then remove the bread to a wire rack to cool completely.
To set up the 3-step breading process, gather 3 medium shallow bowls or plates. In the first, add the flour, 1/2 teaspoon salt and 1/4 teaspoon pepper. In the second, add the eggs and 2 tablespoons of water and whisk well. In the third, add the breadcrumbs, Parmesan and oregano and stir to combine.
Pat the eggplant dry with paper towels. Dredge one round in the flour, shaking off any excess. Now, using your other hand (keeping one hand dry and one hand wet), dip into the egg mixture to coat completely. Finally, dredge in the breadcrumb mixture and coat completely. Set on a parchment-lined baking sheet and repeat the process with the remaining eggplant.
Add 1/2 inch of vegetable oil to a 12-inch heavy-bottomed skillet, set over medium-high heat and heat to 375 degrees F. In batches, fry the eggplant until golden brown, 1 to 2 minutes per side. Transfer to paper towels to dry.
Slice the bread ring horizontally to build your giant sandwich. Layer on the mozzarella, pepperoni, eggplant, roasted red pepper, oven-roasted tomatoes and banana peppers. Carefully slice the sandwich into 8 pieces and enjoy! Or wrap in foil and bring to tailgate.