Preheat your oven to 350°F (175°C). Line an 8-inch round cake pan with baking paper.
In a mixing bowl, whisk the eggs, then add the almond flour, honey, baking powder, and lemon zest (if using) mixing gently until smooth.
Pour the batter into the prepared pan.
Sprinkle with almond flakes.
Bake for 20-25 minutes, or until a toothpick inserted in the centre comes out clean.
Allow to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
