Spread the slivered almonds onto a baking sheet, and toast until the nuts start to turn golden brown and become fragrant, 5 to 10 minutes. Watch the nuts carefully as they bake, because they burn quickly. Once toasted, set the nuts aside to cool to room temperature.
Mix together the mayonnaise, milk, and sugar in a large salad bowl. Stir in the bacon bits and Parmesan cheese until the dressing is well combined and creamy.
Place the spinach leaves, chopped cauliflower, and toasted almonds into the salad bowl, and stir lightly to coat with dressing.