Peel the apple and finely grate it using the small holes of a box grater. Gently squeeze out excess liquid with your hands, but do not press it completely dry. The grated apple should remain moist without dripping.

In a large bowl, whisk together the almond flour, coconut flour, baking powder, cinnamon, and salt until evenly combined.

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

Pour the wet ingredients into the dry ingredients and stir with a rubber spatula until no dry patches remain. Fold in the grated apple. The batter should be thick and scoopable rather than runny.

Let the batter rest for 5 minutes. The coconut flour will absorb some of the moisture, and the mixture should become slightly thicker. If it becomes extremely stiff, stir in 1 tablespoon (15 ml) additional almond milk.

Preheat the waffle maker according to the manufacturer's instructions. Lightly grease the plates with coconut oil if needed.

Scoop about 1/3 to 1/2 cup (80 to 120 ml) batter into the center of each waffle section, depending on the size of your waffle maker. Spread it gently without overfilling the plates.

Close the waffle maker and cook for about 4 to 6 minutes, or until the waffles are deeply golden brown and release easily. Grain-free waffles can require slightly longer cooking than conventional waffles because of their moisture.

The exterior should be firm and browned, while the center should feel set and tender rather than wet. If the waffle is soft or difficult to remove, cook for another 30 to 60 seconds.

Transfer each finished waffle to a wire rack: Avoid stacking them while hot because steam can soften the exterior.

Repeat with the remaining batter, lightly greasing the waffle plates between batches if necessary.

Serve with optional sliced apple, chopped pecans, maple syrup, and a light sprinkle of cinnamon.