Boterkoek

THE NETHERLANDS

The Dutch don’t mess around when it comes to butter in their desserts

Mix the sugar with the flour, salt and lemon zest in a big bowl. Add the soft butter and the egg yolk and knead well.
Make a ball of the dough and leave it in a closed plastic bag in the fridge overnight (I use a ziplock bag).
Take it out of the fridge the next day and let it come to room temperature. Knead it as briefly as possible and push it flat into a large circle. Put it in your baking tin and even it out as much as possible with your hand.
Use a brush to cover the top with a bit of beaten egg. You can decorate with the almonds now, if using, push them into the dough a little bit. If you don't use almonds, use a fork to make a diamond pattern.
Bake at 350℉ for approx. 20 minutes. It should not be hard or crunchy but flaky. Only bake until it's just ready. It's still soft when it comes out of the oven and becomes more firm when the butter firms up.
Leave it in the tin until it firms up. Remove and cool completely before serving.