Preheat oven to 375ºF. Place the stick of butter in the Bundt pan. Place the cake pan in the oven until the butter has melted.: As the oven warms you will hear a soft sizzle as the butter melts against the metal and the kitchen fills with a nutty, toasted aroma. This step primes the pan, ensuring a glossy, slightly crisp outer shell once baked, and those sizzling sounds tell you the pan is properly hot. A common mistake is not warming the pan long enough, which prevents the butter from searing the batter edge, so wait until the butter is fully liquid and moving freely. Avoid burning the butter by checking early rather than leaving the oven door closed for too long.
While the butter is melting, whisk together cornmeal, flour, eggs, buttermilk, and cajun seasoning.: You will notice the batter becoming smooth and slightly thick, with flecks of cornmeal and seasoning distributed throughout. The sound is subtle, a soft whisking rhythm, and the color shifts to a warm yellow. This blending is crucial because it ensures even hydration of the cornmeal and even distribution of the cajun seasoning , preventing pockets of dry flour or clumps. Over mixing is a pitfall to avoid, which can tighten the texture, so whisk until combined and stop when just smooth.
Remove the hot cake pan from the oven and immediately pour the cornbread batter into the pan.: The immediate pour onto the melted butter causes a faint hiss and a rapid settling of batter into the pan, creating those prized buttery ribbons and encouraging a crisp outer edge. The contrast of hot metal and cool batter creates a quick set at the edges, which supports a good crust. If you delay pouring, the butter may cool and congeal which reduces the crisping effect, so have everything ready to transfer quickly. Beware of splatters from hot butter; pour steadily to avoid burns.
Bake for 35 to 45 minutes, until golden brown.: During baking you will see the top take on a warm golden hue and the aroma deepen to a toasted, buttery scent. The center will appear set when a toothpick comes out with a few moist crumbs, and the edges will pull slightly away from the pan. This period is when structure forms, and the heat transforms moisture into steam, creating lift and tenderness. Opening the oven too often is a common error because it lets heat escape and can cause uneven rise, so peek sparingly through the window.
Remove the pan from the oven and let cool in the pan for 5 to 10 minutes before removing the bread from the pan.: Cooling briefly allows the crumb to firm slightly so the loaf releases cleanly, and the scent in the air will soften into warm, comforting notes. You should hear a faint settling sound as the loaf finishes setting. If you try to unmold too early the cornbread can break or crumble, so patience here pays off. If the loaf seems stuck, gently run a thin knife around the edges before inverting onto a rack to avoid tearing.