Begin by trimming the ends off the Brussels sprouts and removing any brown outer leaves. Halve them lengthwise from stem to tip. For particularly large sprouts, quarter them to ensure uniform size and even cooking.

OPTIONAL—To achieve a more tender center, cover the Brussels sprouts in a large bowl with warm tap water and let them soak for 10 minutes. If you prefer a firm texture inside and a crispy exterior, this step can be skipped.

Preheat your air fryer to 375 degrees Fahrenheit, following the manufacturer's instructions (typically about 3 minutes).

After soaking, drain the Brussels sprouts and gently pat them dry with a towel. Wipe out the bowl used for soaking and return the Brussels sprouts to it. If you skipped soaking, place them directly into a large mixing bowl. Drizzle the sprouts with olive oil and season with kosher salt and black pepper, tossing to ensure they are evenly coated. Transfer them to the air fryer basket.

Air fry the Brussels sprouts for 5 minutes. Slide out the basket, give it a good shake to toss the sprouts, and return it to the fryer. Continue cooking for another 5 minutes, then shake the basket again. The sprouts should start to look crispy and nearly done. If they need more time, cook for an additional minute or so. Add the sliced garlic and toss to distribute evenly. Cook for 2 to 4 more minutes, checking frequently and shaking the basket until the sprouts are deeply crispy.

For additional flavor, transfer the Brussels sprouts to a serving bowl and mix in any desired toppings. Serve immediately while hot and enjoy!