Place white chocolate in a food processor; cover and process until finely chopped.

In a small saucepan combine whipping cream and butter; cook over medium heat just until simmering (don’t allow mixture to boil), stirring from time to time. Remove from heat.

With the food processor running, carefully pour hot cream mixture through the feed tube into the finely chopped white chocolate. Process until smooth, stopping to scrape sides of bowl if necessary. If during processing the mixture appears to break (the oil separates out of the white chocolate), continue to process until the mixture becomes smooth again and has the thick texture of cake batter. Add desired flavoring; process briefly to mix well. Transfer white chocolate mixture to a large bowl; chill for 2 to 3 hours or until very firm.

To shape truffles, line a baking sheet with parchment paper or waxed paper; set aside. Dust your hands with powdered sugar. Divide white chocolate mixture into 16 portions. Form each portion into a ball. Roll one end of every ball between your palms and pinch it gently to make an egg shape. Place egg shapes on the prepared baking sheet. Chill while you prepare the candy coating.

Place 1/3 of the vanilla-flavor candy coating disks in a medium microwave-safe bowl. Microwave according to package directions until melted and smooth, stirring every 30 seconds. Using a microwave-safe bowl for each color of candy coating, microwave each color according to package directions until melted and smooth, stirring every 30 seconds.

Using a spoon for each color, drizzle several colours of candy coating on top of the melted vanilla coating. The colours will mix together as you dip the truffles, so try to choose colours that blend well and will not instantly produce a muddy color. Don’t worry about swirling them together; the dipping process will try this.

Submerge a truffle totally in the coating. Using a fork or dipping tools, carefully lift truffle out of the coating, swirling it around a little to ensure the top is coated with a number of colours. Return the coated truffle to the paper-lined baking sheet. Repeat with another truffle.

After several truffles, the colours will become vague. At this point, drizzle more coloured coating on top of white coating to get vibrant swirls. When the melted vanilla coating is too low to dip or is no longer white, melt a fresh batch of vanilla candy coating. Repeat until all the truffles have been coated.

Chill coated truffles about 15 minutes or until coating is set. For the best taste and texture, let truffles stand at room temperature for 15 to 30 minutes before serving.