In a large baking tray, add the pumpkin seeds, and the olive oil. Mix thoroughly to coat.
Add the ground paprika, ground cumin, chili flakes, and salt. Mix everything together.
Roast the pumpkin seeds for 20 to 30 minutes, stirring the pumpkin seeds once or twice throughout that time. When they are crisp, fragrant, and beginning to color, remove the baking tray from the oven.
Wait for the pumpkin seeds to cool completely before serving, then transfer them to an airtight container, and use within 1 month.