Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente (usually about 9-11 minutes). Drain and set aside.
While the pasta cooks, dice the poblano peppers into small pieces. If you want a milder flavor, remove the seeds. Dice the cooked chicken into bite-sized pieces.
In a large mixing bowl, combine the softened cream cheese and sour cream. Stir until smooth. Add garlic powder, onion powder, chili powder, salt, and pepper. Mix well to distribute the spices evenly.
Add the drained penne pasta, diced chicken, poblano peppers, and corn kernels into the bowl with the creamy sauce. Toss everything gently to coat all the ingredients in the cheesy mixture.
Stir in 1 ½ cups of shredded cheddar cheese into the pasta mixture. Pour everything into your prepared baking dish and spread it evenly.
Sprinkle the remaining ½ cup of cheddar cheese over the top. Bake in a preheated oven at 350°F (175°C) for 25-30 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let it cool for 5 minutes. Sprinkle sliced green onions on top for a fresh, vibrant finish. Serve warm and enjoy!