Sometimes we are lucky to get beautiful eggs from Hinterstalden, the farm where my sister-in-law’s sweetheart lives.

And sometimes we get lots of them.

When my mother-in-law, Josy, has a surplus, she makes a tender and tart lemon cake that uses nine eggs. I’ve dubbed it the Hinterstalden Lemon Cake, but the original recipe was something that Josy clipped from a magazine years ago.

The author of the original recipe is Annemarie Lüthi, a farmer from the Ruedertal whose farm was featured in this Aargauer Zeitung article from 2016 (photo of the original recipe clipping, below).

This cake is quick and simple to make, and easily feeds a crowd.

Cake:

400 g sugar

zest of 3 lemons

9 eggs

375 g butter, melted

125 ml lemon juice

1 tbsp vanilla paste or extract

475 g flour

15 g baking powder

Glaze:

200 g icing sugar

60 ml lemon juice

Preheat oven to 200 C / 400 F / gas mark 6.

Line a large baking sheet with parchment paper or aluminum foil.

In a large bowl, add the sugar and zest the lemons directly into the bowl. Use your fingers to rub this into the sugar, until it becomes fragrant.

In a large measuring cup, whisk together the vanilla and eggs, then whisk this into the sugar. Whisk the melted butter and lemon juice into the sugar mixture as well.

With a wooden spoon, mix in the flour. Finally, sift in the baking powder and stir in.

Spread onto your prepared baking sheet and bake for about 15 to 20 minutes, or until the top springs back completely when pressed.

For the glaze, whisk together the lemon juice and icing sugar. Spread over the cake while it is still a little warm.

Let cool then cut into squares or triangles.

• The original recipe instructions are quite succinct (mix together all ingredients), but with a very specific detail at the end: das Backpulver wirklich erst am Schluss darunterrühren, or ‘really wait until the end to mix in the baking powder’.

  Josy highlighted this note when she gave me the recipe and it makes sense. The baking powder begins to work as soon as it is activated by a liquid, and most baked goods containing baking powder or soda benefit from being baked immediately after their batter is mixed.