Preheat oven to 425°F (220°C). Line a large baking sheet with parchment paper.
In a small bowl, whisk together all the ingredients for the Cajun spice blend. Set aside.
Cut the potatoes into 0.5-inch thick fries. Ensure they are uniform in size for even cooking.
In a large bowl, toss the potato fries with olive oil until lightly coated.
Add about half of the Cajun spice blend to the bowl with the fries and toss to coat evenly. Add more spice blend if desired, ensuring all fries are well-seasoned.
Spread the fries in a single layer on the prepared baking sheet.
Bake for 25-30 minutes, flipping halfway through, until golden brown and crispy.
Serve immediately.
Notes
For extra crispy fries, soak the cut potatoes in ice water for 30 minutes before patting them thoroughly dry. This removes excess starch.