Preheat the air fryer to 400ºF and coat the basket with 1 teaspoon of avocado oil.
Mix the red onion with vinegar and ¼ teaspoon of salt in a bowl. Set aside.
Toss Brussels sprouts with 2 tablespoons of avocado oil and ½ teaspoon of salt. Air fry until crispy.
Air fry almonds with maple syrup, poppy seeds, and flaky sea salt until golden.
Combine Brussels sprouts, raisins, onions (plus vinegar), and almonds in a bowl.
Shake all dressing ingredients in a mason jar until combined. Pour over the salad and toss.
Top with parmesan cheese and enjoy!