Preheat oven to 400 degrees F. and line two baking sheets with parchment paper.
Slice the cabbage into 1-inch-thick rounds and place them on the baking sheets in a single layer. Brush the tops with olive oil and sprinkle with garlic powder, paprika, salt and pepper.
Roast until the cabbage is tender and edges are golden, 40 to 45 minutes.