Preheat your oven to 350 degrees F. Line 8 muffin cups with paper liners and spray the liners with nonstick spray (I use avocado oil spray). Or use greased silicone cups.
In a large bowl, whisk together the eggs, salt, garlic powder, and cayenne.
Using a rubber spatula, mix in the almond flour, then the baking soda, and finally the cheeses. The batter will be thick and dough-like. You can actually work it with your hands, as shown in the video, although it's quite sticky.
Using a 4-tablespoon scoop, divide the batter evenly between the muffin cups.
Bake until the muffins are golden and a toothpick inserted in their center comes out clean, 22-25 minutes.
Cool the muffins for 5 minutes in the pan, then transfer them to a cooling rack to cool for 5 more minutes before serving.
Video
Notes
*Occasionally, baking soda can cause a reaction in baked goods that results in an unpleasant ammonia smell. If you're concerned about it happening, you could use ½ tablespoon of gluten-free baking powder instead of baking soda. Make sure the baking powder is fresh and not expired. Do make sure you use blanched, finely ground almond flour and not coarse almond meal. It's possible that almond meal would work, but the texture could be dense and not as fluffy, and you also risk the muffins coming out too dry.