In a medium bowl, whisk together the Greek yogurt, cider vinegar, allulose, mustard, and salt until smooth and well combined. The allulose will help create a balanced sweetness without any artificial aftertaste, and whisking ensures the mustard distributes evenly for consistent flavor throughout. Set the dressing aside while you prepare the other components.
While the dressing sits, cook the bacon in a large skillet over medium-high heat until crispy, about 8-10 minutes. Once cooked, transfer to a paper towel-lined plate to drain, then chop into bite-sized pieces. Meanwhile, cut your broccoli into small florets (about the size of a grape for the best texture), finely dice the red onion, and roughly chop the pecans. I like to chop everything into similar-sized pieces so each bite has a balanced mix of textures and flavors.
In a large bowl, combine the broccoli florets, diced red onion, chopped pecans, shredded cheddar cheese, sunflower seeds, and cranberries. Pour the dressing from Step 1 over the vegetables and toss gently but thoroughly until everything is evenly coated. Add the chopped bacon from Step 2 and fold it in gently to distribute throughout. I prefer to add the bacon at the end rather than mixing it in earlier—this keeps it crispier longer, especially if you're making this ahead. Taste and adjust seasoning with black pepper as needed.