Preheat the oven to 450°F. Line a rimmed baking sheet with high-heat-resistant parchment paper or nonstick foil and coat it with avocado oil.
Avocado oil spray
Cut the chicken breasts into bite-sized pieces, about 1.5 inches. Pat them dry with paper towels.
2 chicken breasts
In a small bowl, whisk together the egg, salt, black pepper, garlic powder, and cayenne pepper. Place the almond flour in another bowl.
1 large egg, ¼ teaspoon sea salt, ¼ teaspoon black pepper, ½ teaspoon garlic powder, ¼ teaspoon cayenne pepper, 1 cup superfine almond flour
Dip each piece of chicken in the egg mixture, then dredge it in the almond flour, pressing to coat. To avoid a sticky mess, use one hand to dip in the egg and the other to dredge in the almond flour.
Arrange the chicken pieces in a single layer on the prepared baking sheet. Spray them lightly with avocado oil. Bake until the bottom is golden, about 8 minutes.
Carefully flip, spray with more oil, and bake for about 8 more minutes, until golden and cooked through. Their internal temperature should reach 165ºF.
To promote browning, if your baking dish is broiler-safe and lined with foil (not parchment), finish by broiling the chicken nuggets in the middle of the oven for 2-3 minutes per side, or until golden brown. Watch them closely to ensure they don't burn.
Serve immediately.
Video
Notes
Seasonings, especially salt, are just guidelines. Adjust to taste.
You won't use all the almond flour. You'll only use about half. But you need all of it to properly dredge the chicken pieces. The nutrition info reflects that.
The coating won't be as crispy as breadcrumbs, but we don't want it soggy. To achieve this, don't crowd the nuggets on the baking sheet. You can use an oven-safe wire rack to promote airflow. Sometimes, the chicken is fully cooked, but the coating is still pale. When this happens, I switch the oven to broil and replace the parchment paper with foil. I broil the nuggets in the middle of the oven (not directly below the element) for 2-3 minutes per side, until they are nicely browned. They won't all brown at the same time. Switch them around on the pan or remove the browned ones to a plate, then keep broiling the rest.
You can keep the leftovers in an airtight container in the fridge for 3-4 days. Reheat them uncovered in a 350°F oven. The almond flour coating is a bit fragile, so handle the nuggets carefully. I don't recommend freezing them.