Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper for easy cleanup.
Spread each bagel half open and place them cut-side up on the baking sheet.
Mix together the tomato sauce with the grated zucchini, minced garlic, oregano, and a pinch of salt if desired. This creates a flavorful, slightly veggie-filled base for the toppings.
Spread a generous spoonful of the zucchini-tomato sauce evenly over each bagel half, covering the surface completely.
Sprinkle the shredded cheese evenly over the sauce on each bagel, creating a gooey, cheesy layer.
Place the baking sheet in the oven and bake for about 10 minutes, or until the cheese is melted, bubbly, and starting to turn golden at the edges.
Remove from the oven and let sit for a minute until the cheese cools slightly and sets just enough to hold together.
Slice or serve the bagel pizzas directly from the baking sheet, enjoying their crispy edges and chewy, cheesy tops.