Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper for easy cleanup.
Slice the polenta tube into rounds about ¼ to ½-inch thick. You should get around 24 slices.
This step is crucial: Arrange the polenta slices in a single layer on a clean kitchen towel or paper towels and pat the tops completely dry. Removing surface moisture is essential for getting them crispy.
Place the dry polenta rounds on the prepared baking sheet. In a small bowl, mix the olive oil, salt, pepper, and garlic powder. Brush this mixture evenly over both sides of each polenta slice.
First Bake (The Crisping Stage): Bake for 15 minutes, flipping the rounds halfway through, until they are firm and the edges are golden brown and crispy.
Remove the baking sheet from the oven. Carefully top each crispy polenta round with about 1 teaspoon of pizza sauce, followed by a sprinkle of mozzarella cheese, a few pieces of mini pepperoni, and a dash of Italian seasoning.
Second Bake (The Melting Stage): Return the baking sheet to the oven and bake for another 5-7 minutes, or until the cheese is bubbly, melted, and slightly golden.
Let the Polenta Pizza Bites cool on the baking sheet for a few minutes to set before transferring to a serving platter. Garnish with fresh basil or parsley if desired and serve warm.
