Cook the bacon in a skillet over medium-high heat, flipping occasionally, until crispy, about 10 minutes.
Transfer to paper towels to drain, crumble, and set aside.
Arrange chopped lettuce at the bottom of a large glass dish or bowl.
Add a layer of finely sliced red onion over the lettuce.
Spread peas evenly across the onion layer.
Sprinkle shredded cheese over the peas to form the next layer.
Distribute chopped cauliflower over the cheese layer.
Scatter the crumbled bacon on top of the cauliflower.
In a bowl, mix mayonnaise, Parmesan cheese, and sugar until the dressing is smooth and creamy.
Pour the dressing evenly over the layered salad, cover, and chill in the refrigerator until ready to serve.