Or you could just abstain from casting a bonus action spell if you want to retain the ability to counterspell a possible counterspell...
In practical terms, Sorcerers can't protect their Quickened spells from Counterspell, since you aren't allowed to cast a non-cantrip spell on your own turn if you cast your spell using a bonus action.
This is probably okay. Cast the spell at regular speed if you're worried about getting counterspelled.
Why would I? Since I view counterspell as more specific than the bonus action rule, counterspell can be cast any time, including on a creature's turn when they cast both a cantrip and a bonus action.