Heat the oven to 400 F. Lightly coat a baking sheet with cooking spray. In a large bowl, add the Canadian bacon, onion, tomato, roasted red pepper, pineapple and salad dressing. Mix well.
On a floured surface, cut the dough into quarters. Press each piece into a circle. Using a rolling pin, roll the dough into an oval. On each oval, add the Canadian bacon mixture and 1 tablespoon cheese. Fold the dough over the filling, pressing the edges together. Crimp with a fork and place on the prepared baking sheet.
Brush the calzones with the olive oil. Bake until golden brown, about 10 minutes. Top each with 1/4 cup warmed tomato sauce, sprinkle with oregano and serve immediately.