1. CREAM together the butter, sugar and vanilla until light and fluffy. Gradually beat in the eggs, beating well between each addition. Add the flour and milk and stir until combined. Fold through the chocolate. Spoon the mixture into 12 x 1/3 cup capacity paper lined muffins pans.
2. BAKE in a moderate oven 180°C for 20 minutes or until cooked when tested. Cool on a wire rack for 10 minutes before turning out onto a wire rack. Cool.
3. BEAT the extra butter until pale and creamy. Add the vanilla, then beat in the icing sugar and milk in 2 batches. Chill until firm enough to spread.
4. ICE each cupcake with some buttercream. Cover a cone with buttercream and roll in sprinkles and cachous to coat then press on top of a cake. Repeat with remaining cones and buttercream. Chill until firm then use as required.