I used what I could get my hands on: Antica Distilleria Quaglia Violetta Liqueur as Creme de Violette is no where to be found. I added some syrup from Amarena Fabbri. David Selle's comment of adding the violette to the glass first and shaking the rest resulted in a delightful cocktail.

I tried it with both lime and lemon juice and prefer the lime (same with the 20th Century).