Negroni Sbagliato, one of my favorite little-known low-proof wonders. A great patio drink, or a tasty way to avoid getting too drunk - your choice.
3/4 oz sweet vermouth
3/4 oz Casoni 1814 (or comparable; Aperol would actually be best)
3/4 oz reposado tequila (Espolon)
3 oz sparkling wine (a lovely gifted blanc de blanc this time; normally I'd be using cava)
3 dashes Bitter Truth Xocolatl Bitters
Build over copious ice in a tall-ish glass; doesn't really matter what kind as long as it will hold your beverage. Garnish with a grapefruit peel (that's lemon in the picture, because I didn't have any grapefruit around, but I'm expressing a preference for once).
I'm making this as a pitcher-sized cocktail for the first warm day when we have people over - just you watch. Nice easy proportions make this easy to scale up or down.