Finely dice the red bell pepper, yellow onion, and zucchini. For the best flavor and to prevent soggy pinwheels, gently sauté these diced vegetables in a non-stick skillet over medium heat for 5-7 minutes until they've softened slightly and any excess moisture has evaporated. Let them cool down a bit while you prepare the pastry.

Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper to prevent sticking and make cleanup a breeze.

On a lightly floured surface or directly on its provided parchment paper, carefully unroll one sheet of thawed puff pastry. Spread half of the pizza sauce evenly over the pastry, making sure to leave a small border (about 1/2 inch) around the edges. This helps seal the roll later.

Sprinkle half of the shredded mozzarella cheese over the pizza sauce. Evenly distribute half of your sautéed diced vegetables across the cheese, followed by half of the Italian seasoning and garlic powder. Don't overfill, or it will be hard to roll.

Starting from one of the long edges, carefully and tightly roll the pastry into a log. Once rolled, gently pinch the seam to seal it completely. Repeat this entire process with the second puff pastry sheet and the remaining sauce, cheese, vegetables, and seasonings.

Using a sharp knife, slice each pastry log into 1-inch thick rounds. You should get approximately 12-14 pinwheels from each log, making about 24-28 total.

Arrange the pinwheels cut-side up on your prepared baking sheet, leaving a little space (about 1/2 inch) between each one for even baking. Sprinkle the tops with the grated Parmesan cheese. Bake for 18-22 minutes, or until the pastry is beautifully puffed and golden brown, and the cheese is bubbly and slightly caramelized. If they start browning too quickly, you can loosely tent them with foil.

Let the pinwheels cool on the baking sheet for 5 minutes before serving. This allows them to set up slightly and makes them easier to handle.