Place milk, glucose syrup and caster sugar in a saucepan over medium heat and stir for 2-3 minutes until sugar dissolves. Remove from heat and cool slightly.
Whisk egg yolks until pale, then slowly pour the warm milk mixture into the yolk mixture, whisking constantly.
Return mixture to saucepan and place over low heat, stirring constantly with a wooden spoon for 5 minutes or until slightly thickened and smooth. Strain, then set aside to cool.
Whisk cream in a bowl to soft peaks and gently fold cream, creme fraiche and Elderflower Flavour into the cooled custard.
Chill until cold in your fridge. Transfer to an ice cream machine and churn according to the manufacturer’s instructions. If you don’t have an ice cream maker, you can still achieve a fluffy and smooth texture by freezing in a shallow container and pulling it out every half hour to mix with a hand mixer that will break the ice crystals and make the ice cream smooth.