On the top of my list of favourite champagne/sparkling wine cocktails is to mix the bubbles with
1/4 oz/10mL Chambord (Black Raspberry Liqueur). Add Chambord to the flute first, them add the Champers. Perhaps a touch more if you like it sweeter, like me

Stay tuned, I'll post another recipe tomorrow because I love to experiment and the side effects of consuming the prototypes isn't half-bad, but someone has to do it