Preheat oven to 375°F. Line a sheet pan with foil.
In a mixing bowl, toss the halved baby potatoes with Cajun seasoning and enough olive oil to fully coat.
Spread potatoes evenly on the sheet pan and bake for 30 minutes.
Turn the oven to broil and cook for an additional 5 minutes, until lightly browned. Set aside.
In a Dutch oven or large pot, add bacon to a cold pan. Turn heat to high and cook until crispy.
Remove bacon with a slotted spoon and set aside, leaving the bacon fat in the pot.
Add celery, red bell pepper, and onion to the bacon fat. Season with additional Cajun seasoning to taste.
Cook for 5–6 minutes, until the vegetables are softened and fragrant.
Add garlic and cook for about 1 minute, until fragrant.
Stir in the flour and cook for 3–4 minutes, stirring constantly. This creates a roux and helps thicken the chowder.
Slowly pour in the chicken broth, whisking or stirring continuously to prevent lumps.
Add the frozen corn and heavy whipping cream.
Cover and cook for about 10 minutes, stirring occasionally, allowing the chowder to thicken and the flavors to blend.
Add the roasted potatoes and cooked bacon to the pot.
Stir well and allow everything to heat through.
Taste and adjust the Cajun seasoning if needed.
Serve hot, topped with extra bacon and grated Parmesan cheese.