Bring a large pot of water to a boil. Cook the cauliflower for 3-4 minutes until softened. Drain and set aside.
Heat a skillet over medium heat and cook the bacon for 6-7 minutes until light brown and crispy. Remove the bacon to a paper towel-lined plate, leaving the fat behind.
Preheat your oven to 400°F.
Pour out some of the fat so that you have about 2 tablespoons left in the skillet. Add the onions and cook for 4-5 minutes until softened. Add the garlic and cook for another minute. Remove from the heat.
Add the cream cheese to the skillet and use a fork to mash it together with the onions. The residual heat should help soften the cream cheese.
Stir in the sour cream and 1 cup of the cheddar cheese. Gently fold in the cauliflower.
Transfer the mixture to a large casserole dish. Top with the remaining cheddar cheese and bacon bits. Bake for 25-30 minutes until the cheese is lightly browned and the sides are bubbling up. Sprinkle scallions or chives on top.
Nutrition information is calculated using an ingredient database and should be considered an estimate.