Shred the squash in your food processor using the shredding attachment. Place on clean towels and allow to drain for 10 minutes. You can also grate the squash by hand.
Finely chop the onion. Place it in a colander to drain for 10 minutes.
Heat a large nonstick skillet over medium heat for about 5 minutes.
In a medium bowl, whisk the egg with salt, black pepper, and garlic powder. Add the grated squash and the onion and mix to blend.
Brush the skillet with half of the butter. Measuring ¼ cup per fritter, spoon the mixture onto the skillet. Fry without moving for 4-5 minutes, until you can see that the bottoms are browned.
Carefully flip to the other side and fry for 4-5 more minutes, until browned on both sides. Brush the skillet with more butter and repeat with the remaining squash mixture.
Video
Notes
Lacking starch, these fritters are quite fragile, so flip them very carefully. The more water you get out of the squash and onion, the sturdier they will be.You can also try adding flour (if you don’t mind the gluten) or coconut flour to absorb the extra liquid. Try 2 tablespoons of coconut flour or (if you don't mind the gluten and carbs) ¼ cup of all-purpose flour.