1. Preheat oven to 350°F (175°C) and grease two 8-inch (20 cm) round cake pans

2. In a large bowl whisk together almond flour, baking powder, and salt

3. In another bowl whisk the eggs, sugar, and melted margarine or butter until smooth

4. Add the cooked potatoes, lemon zest, and lemon juice to the egg mixture and mix until smooth

5. Gradually add the dry ingredients to the wet ingredients mixing until just combined

6. Divide the batter evenly between the prepared pans and smooth the tops

7. Bake for 25 to 30 minutes until a toothpick inserted in the center comes out clean

8. Let cool in the pans for 5 minutes then transfer to a wire rack to cool completely

9. Serve plain or with a light dusting of powdered sugar