These jam-filled hearts from Zurich are also known as Züri Nüssli and piped into clamshell shapes. Buttery and chocolate-dipped, they are a filled version of a spritz cookie, the delicate treats often served in Germany at Christmas time, but here, heart-shaped, they are perfect for Valentine’s Day too.

I have a recipe for these cookies in my book Swiss Cookies (here’s the German version too), and they are a firm family favourite.

Keeping the dough cool is essential for keeping the nice piped shape of the cookie. You can fill them with any jam of your choosing—here I used raspberry, but they also taste great with apricot, strawberry or cherry.

Dough

200 g butter, soft

80 g icing sugar

2 egg yolks (30 g), room temperature

pinch of salt

250 g flour

Assembly

150 g jam

150 g dark chocolate, melted

Cream together the butter and sugar until pale and fluffy. Beat in the yolks and salt. Sift in the flour and stir until combined.

Using a piping bag with a star tip 1 cm in diameter, pipe 24 hearts. Pipe two lines about 6 cm each in a ‘V’ shape, then wet your fingers and press the tails together to make a heart shape.

Chill in the freezer for about 15 minutes, until firm.

When you are ready to bake

Preheat the oven to 180° C.

Bake the cookies for about 8–10 minutes, or until they are set and the bottoms are golden. Let cool completely.

Assembly

Sandwich about a tablespoon of jam between two cookies. Dip one side into melted chocolate

• My original recipe doesn’t call for it, but I sometime like to add a teaspoon of vanilla paste or extract to the dough.

• Because this is a stiff dough, and it can be a bit challenging to pipe, you want to make sure that your butter is quite soft and that the yolks are at room temperature. You can do this by placing the butter in a bowl, and then resting this in a sink of hot water, and putting the eggs in hot water too, before you crack then open (more here).

• At the same time, you really want the cookies to be cold before putting them in the oven, so the butter doesn’t run out. The best way to do this is to pop them in the freezer for 15 minutes (though you could also sit them in a cold cellar or balcony).