Black and White Cookies
Combine flour, butter, powdered sugar, water and salt.
Divide dough in half and add milk, cocoa and cinnamon to one-half the dough. Wrap both portions of dough with plastic and chill for 2 hours.
Roll out each portion of dough on a floured surface. Cut dough into strips, 5 cm (approximately 2 inches) wide.
Brush strips with egg whites and layer strips, 3 light and 3 dark per stack. Slice strips into cookies and place on a baking sheet lined with parchment paper.
Bake in an oven preheated to 190°C (approximately 375°F) for 10-12 minutes. Remove, let cool and serve.