Step 1: Preheat and Prepare the Dish - Start by preheating your oven to 350 degrees. Grab a 9 by 13 baking dish and set it out on the counter. I like to give mine a light grease just to be safe, though the topping does a good job of preventing sticking. Getting your oven ready first means everything else flows smoothly once you start assembling.
Step 2: Mix the Creamy Topping - In a medium bowl, combine the mayonnaise, softened cream cheese, chopped green onions, crumbled bacon, and one cup of the shredded Colby Jack cheese. Use a fork to mix everything together. This is one of those little tricks that really helps break up the cream cheese and get everything evenly combined. Take your time here because a smooth mixture means a better texture once it bakes.
Step 3: Arrange the Chicken - Place the chicken breasts into your prepared baking dish in a single layer. If they are thick, make sure they have been slightly pounded or sliced thinner so they cook evenly. This step makes all the difference between juicy chicken and something that turns out dry.
Step 4: Add the Topping - Spoon the cream cheese mixture over each piece of chicken and spread it out so it covers the top completely. Do not worry about making it perfect. Just make sure each piece gets a generous layer. Then sprinkle the remaining half cup of shredded cheese evenly over the top.
Step 5: Bake to Perfection - Place the dish in the oven and bake for 30 to 35 minutes. You are looking for the chicken to reach an internal temperature of 165 degrees and the top to be bubbly and lightly golden. The smell at this point is going to pull everyone into the kitchen, and honestly, that is one of the best parts.
Step 6: Finish and Serve - Once it is out of the oven, let it rest for a few minutes. If there is any liquid in the bottom of the dish, carefully pour it off. Then, if you like, sprinkle a little extra bacon or green onions on top for a fresh finish. Serve it warm over mashed potatoes or alongside your favorite sides.