Preheat your oven to 375°F (190°C). Pat the chicken breasts dry and season evenly with salt, garlic powder, and black pepper. Sear in olive oil over medium-high heat for 2-3 minutes per side until light golden. Transfer to a white ceramic rectangular baking dish.

In the skillet, melt the butter over medium heat. Whisk in the flour and cook for 1 minute. Slowly whisk in the heavy cream until simmering and thickened. Reduce heat to low and stir in the softened cream cheese until luxuriously smooth.

Pour the thick white cheese sauce entirely over the seared chicken breasts. Evenly sprinkle the shredded cheddar and mozzarella cheeses over the top to create the crust layer.

Bake uncovered for 20-25 minutes until the chicken reaches 165°F (74°C). Switch the oven to broil for 2-3 minutes until the cheese develops a bubbling, golden-brown crust with slightly charred, crispy edges.

Remove from the oven and let rest for 5 minutes. Scatter the crispy chopped bacon bits and bright green sliced scallions across the melted cheese surface before serving.