Preheat the oven to 350°F (175°C). Line a 9" x 5" loaf pan with parchment paper, leaving some overhang to lift the loaf out after baking.

In a large bowl, whisk together the wet ingredients: 3 large eggs, 2/3 cup pure maple syrup, 2 Tbsp avocado oil, and 2 tsp vanilla extract until smooth and combined.

In a separate large bowl, stir together the dry ingredients: 2 cups finely ground almond flour, 1/2 cup tapioca flour, 1/2 cup raw cacao powder or cocoa powder, 1/2 tsp sea salt, 1 tsp ground cinnamon, and 2 tsp baking powder until evenly combined.

Pour the dry ingredients into the wet ingredients and gently stir with a spatula or spoon until a smooth, uniform batter forms, scraping the sides and bottom of the bowl. Avoid vigorous mixing.

Stir in 2/3 cup chocolate chips, if using, until distributed evenly through the batter.

Pour the batter into the prepared loaf pan and smooth the top with a spatula. If desired, sprinkle a few extra chocolate chips on top.

Cover the loaf pan with aluminum foil and place on the center rack of the preheated oven. Bake covered for 30 minutes.

Remove the foil and continue baking uncovered for an additional 15–20 minutes, until the bread is baked through. The bread is fully cooked when an instant-read thermometer inserted into the center registers 190°F, or when a toothpick inserted into the center comes out with moist crumbs but no raw batter.

Remove the loaf from the oven and let it cool in the pan for 10–15 minutes. Use the parchment overhang to lift the loaf from the pan and transfer it to a wire rack to cool completely to room temperature before slicing.

Once cool, slice and serve. Storing: keep slices in an airtight container.