Place the cream cheese, peanut butter and confectioners’ sugar in a small bowl and mix together until combined. Stir in the crumbled shortbread and then mix in the melted white chocolate. Cover the bowl with plastic wrap and place in the fridge for an hour to chill.
After an hour, take the mixture out of the fridge. Line a plate or tray with baking parchment. Scoop out heaped teaspoons of the mix, place in your hand and roll into a ball. Place on the parchment. Repeat until all of the mixture is used up. Place back in the fridge to chill for 30 minutes.
After 30 minutes, take the shortbread balls out of the fridge. Place one of the balls on a fork and dip into the melted semi-sweet chocolate. Use a spoon to drizzle more of the chocolate over the top, then let any excess chocolate drip off. Gently place the ball back on the parchment-lined tray and repeat until all of the mixture is used up. Leave the chocolate to set at room temperature for 30 minutes, then mix the peanut butter with the melted white chocolate and spoon into a piping bag. Pipe little strips of the peanut butter mixture over the top of the chocolate truffles and leave to set in the fridge before serving.