|Butter||4 Ounce (125 Gram)|
|Caster sugar||4 1⁄2 Ounce (2/3 Cup / 140 Gram)|
|Vanilla essence||1 Teaspoon|
|Flour||7 Ounce (1 3/4 Cups / 220 Gram)|
|Cocoa powder||1 Ounce (1/4 Cup / 30 Gram)|
1. Place butter, sugar and vanilla essence in a bowl and beat until mixture is creamy. Add egg and beat until well combined.
2. Divide mixture into two equal portions. Sift 1 cup / 125 g / 4 oz flour into one portion and mix to combine. Sift together cocoa powder and remaining flour and mix into other portion.
3. Roll out each portion between two sheets of greaseproof paper to form a 20 x 30 cm / 8 x 12 in rectangle. Remove top sheet of paper from each and invert one onto the other. Roll up from longer edge to form a long roll. Wrap in plastic food wrap and refrigerate for 1 hour.
4. Cut roll into 5 mm / 1/4 in slices, place on greased baking trays and bake at 180°C/350°F/Gas 4 for 10-12 minutes or until lightly browned. Cool on wire racks.