Preheat Oven & Prep Pan: Heat oven to 350°F (175°C). Grease a loaf pan or line with parchment paper.
Prepare Zucchini: Shred the zucchini, then squeeze out as much water as possible. Moisture is the enemy of fluffy keto bread.
Mix Wet Ingredients: In a bowl, whisk eggs, olive oil (or butter), sweetener, and vanilla until smooth.
Add Dry Ingredients: Fold in almond flour, coconut flour, baking powder, salt, and cinnamon. Mix gently until combined.
Incorporate Zucchini & Cheese: Fold shredded zucchini (and cheese, if using) into the batter. Make sure it’s evenly distributed.
Bake: Pour batter into the prepared pan. Smooth the top and bake for 40–50 minutes, or until a toothpick comes out clean.
Cool & Slice: Let the loaf cool 10–15 minutes before slicing—this helps it hold together.