Heat the oven to 175 C / 350 F. Line a 9x5 inch (23x13 cm) loaf pan with parchment paper, leaving a little overhang on both long sides.

Peel and grate the apple on the large holes of a box grater. Transfer to a clean kitchen towel and squeeze out as much liquid as you can. Set aside.

Whisk together the almond flour, tapioca starch, cinnamon, baking soda, and salt in a large bowl until combined with no lumps.

In a separate bowl, whisk the eggs, maple syrup, melted coconut oil, and vanilla extract until smooth.

Pour the wet ingredients into the dry ingredients and stir until a thick batter forms. Fold in the squeezed grated apple.

Let the batter rest for 5 minutes so the almond flour absorbs the liquid. It will thicken slightly.

Scrape the batter into the prepared pan and smooth the top with the back of a spoon.

Bake for 45 to 50 minutes, until the top is deep golden brown and a skewer inserted in the center comes out with just a few moist crumbs. If the top browns too quickly, tent loosely with foil after 30 minutes.

Cool the loaf in the pan for 15 minutes, then lift out using the parchment overhang and transfer to a wire rack. Cool completely before slicing.