Scoop sherbet into the bowl of an electric stand mixer (or into a large bowl to mix by hand or with an electric hand mixer). Let it soften until mixable, 5-10 minutes.
While the sherbet softens, toss the bananas with the lemon juice (adds a boost of flavor and helps the bananas retain their bright color).
To the sherbet, add the raspberries (with any accumulated juices) and the bananas and lemon juice. Mix until well combined and the raspberries and bananas are in small pieces (continue mixing if you want them broken down even more).
Scoop into a freezer-safe container and freeze until set up, 2-3 hours (or longer). Before serving, let the sorbet sit at room temp for 15 minutes to soften slightly. Scoop into bowls (delicious served with a few thin and crispy lemon cookies) OR scoop into glasses with ginger ale for a fizzy float drink.
Cookies: this is delicious served with thin, crispy lemon or vanilla cookies. I've found the lemon cookies at Trader Joe's or Costco.Ginger Ale: when making this "float-style" I prefer using ginger ale, but you could also use sprite or 7-up.