Piano Key Cookies

12 Ingredients

Number of servings

For the chocolate dough

190grams plain flour
50grams cocoa powder
200grams unsalted butter, cold
65grams icing sugar

For the white dough

250grams plain flour, save 10g for dusting
65grams icing sugar
1 pinch sea salt
200grams unsalted butter, cold
1/2 lemon, zest and juice
2teaspoons vanilla extract

2 egg whites, beaten
1/2 lemon, juiced

Description

With delicate layers of lemon and chocolate biscuit, these beautiful cookies melt in the mouth. They may seem intricate, but you can get impressive results from a simple dough using this layer, slice, and freeze method.

Method

Step 1 of 8

To make the white dough, sift the dry ingredients into a mixing bowl. Beat the butter and lemon juice in a food processor until light and creamy. Add the dry ingredients to the processor, along with the lemon zest and vanilla extract. Pulse the mixture until a dough forms. Remove from the processor, wrap in cling film, and chill.

Step 2 of 8

To make the chocolate dough, sift the flour and cocoa powder into a mixing bowl. Beat the butter and icing sugar in the processor until light and creamy. Add the flour and cocoa powder and pulse until a dough forms. Removefrom the processor, wrap in cling film, and chill.

Step 3 of 8

On a lightly floured surface, knead the white dough for 5–10 minutes until smooth. Form into a flat rectangle using your hands. Place the dough between 2 large sheets of baking parchment and roll into a large rectangle about 3–5mm thick. Remove the top layer of parchment and lift the dough, with the parchment beneath, onto a baking sheet. Brush the top of the dough with the beaten egg white.

Step 4 of 8

Knead and roll out the chocolate dough in the same way, and place it on top of the white dough. Use a knife to neaten and trim the edges so that the players are the same size. Brush the top of the chocolate layer with the egg whites, and place the dough in the freezer for 1 hour.

Step 5 of 8

Remove the dough from the freezer. Use a large, sharp knife to cut the dough in half lengthways. Brush the top of one half with egg, and carefully layer the other half on top, so that the colours alternate.

Step 6 of 8

Cut the dough in half lengthways again, brush the top of one layer with egg wash, and place the other half on top. You should now have a long, thin strip of 8 layers of dough in alternating colours. Place in the freezer for 1 hour.

Step 7 of 8

Remove the dough from the freezer. Cut vertical slices lengthways through the layers, about 3–5mm thick. Then, cut these long strips into 4cm square cookies. Place on a lined baking sheet. Preheat the oven to 180°C and allow the cookies to come to room temperature.

Step 8 of 8

Bake the cookies for 12–15 minutes until just turning golden brown. Once cooked, allow the cookies to cool completely before removing them from the baking sheet. You can store the cookies in an airtight container at room temperature for up to 5 days.