For Cookies: Preheat oven to 180 degree. Line baking trays with baking paper. Using an electric mixer, beat butter, sugars and vanilla essence for 1-2 minutes or until smooth and well combined. Beat in egg until combined.
Stir in flour in two batches. Stir in dark and milk chocolate bits. Roll 2 level tablespoonfuls of mixture into balls and place on prepared trays, 3 cm apart. Press down slightly. Decorate with extra chocolate bits.
Bake for 15-18 minutes or until light golden and cooked. Transfer to a wire rack to cool. Store cookies in an airtight container for up to 1 week.
For Sandwiches:Let the cookies cool for at least 30 minutes. Once cool, put a scoop of ice cream between two cookies and Roll the edges of the ice-cream sandwiches in the mini chocolate chips or colourful sprinkles. Serve it immediately..ENJOY