Cook the bacon in a skillet over medium heat until it's crispy and golden, about 8-10 minutes, then transfer to a paper towel-lined plate and crumble once cooled. While the bacon cooks, bring a pot of salted water to a boil and add the eggs, then simmer for 10-12 minutes until hard-boiled. Transfer the cooked eggs to an ice bath to cool completely, then peel and chop them into roughly 1/2-inch pieces. I like to start with the bacon and eggs since they require the most hands-off cooking time and can cool while you prepare the other components.
Preheat your oven to 400°F while you prepare the cauliflower. Cut the large head of cauliflower into 1-inch florets and toss them on a baking sheet with the olive oil, salt, and cracked black pepper, spreading them in a single layer. Roast for about 25 minutes, stirring halfway through, until the florets are golden brown and tender with some crispy edges. Remove from the oven and let cool to room temperature—this prevents the warm cauliflower from melting the mayo and sour cream when mixed together.
In a large mixing bowl, combine the mayonnaise, sour cream, Dijon mustard, garlic powder, smoked paprika, pickle juice, and fresh dill. Whisk these ingredients together until smooth and well combined, tasting as you go and adjusting the seasonings to your preference. The pickle juice adds a subtle tang that ties the whole salad together while the mustard and paprika build depth of flavor.
Add the cooled roasted cauliflower from Step 2 to the creamy dressing base from Step 3, then fold in the crumbled bacon and chopped eggs from Step 1. Gently stir in the shredded cheddar cheese, diced dill pickles, and sliced green onions, being careful not to break up the cauliflower florets too much. Toss everything together until the cauliflower is evenly coated with the dressing, then taste and adjust salt and pepper as needed. I find it's best to fold everything together gently rather than aggressively mix, which helps keep the cauliflower florets intact and gives the salad a better texture.