- STEP 1
Line a 20 or 23cm (8 or 9 in) square tin with greaseproof paper.
- STEP 2
In heavy saucepan over low heat, melt plain chocolate with 250ml condensed sweetened milk and vanilla. Spread half of the mixture into prepared tin; chill 10 minutes, or until firm. Reserve remaining chocolate mixture at room temperature.
- STEP 3
In another heavy saucepan over low heat, melt white chocolate with remaining condensed sweetened milk (mixture will be thick.) Stir in peppermint extract and food colouring, if using. Spread this mixture on chilled plain chocolate layer; chill 10 minutes, or until firm.
- STEP 4
Spread reserved plain chocolate mixture over the mint layer; chill 2 hours, or until firm. Cut into squares and store in an airtight container.