Black and white swirl cookies

• plain flour↗300g g
• powdered sugar↗100g g
• vanilla sugar↗8g g

  or 8 g caster sugar, plus 1 tsp vanilla extract

• egg↗1

  plus 1 egg white for glaze

• butter↗125g g

  softened

• cocoa↗1 tbsp tbsp
• milk↗1 tbsp tbsp

Step-by-step instructions

1. 1

   Place the flour, powdered sugar, vanilla sugar, a pinch of salt, the egg and softened butter in a mixer and combine. Turn the dough onto a lightly floured work surface and briefly knead by hand. Cut the dough in half. Wrap one half and chill for an hour. Into the other half fold in the cocoa and milk. Wrap and chill for another hour.

2. 2

   Roll each portion of dough into a rectangle (about 30 cm × 20 cm) on a lightly floured surface. Brush the top of one layer with egg white, then cover with the other colored dough and brush the top again with egg white. Tightly roll up like a Swiss roll. Wrap and chill for 30 minutes.

3. 3

   Preheat the oven to 175 °C (convection 155 °C, gas 3½). Line two baking trays with parchment paper. Cut the dough into slices about 5 mm thick with a sharp knife. Bake in batches for 10–12 minutes, but do not let the light dough darken to preserve the contrast. Allow to cool completely.