You run the risk of food poisoning from anything you get from the stores nowadays......
Fresh fruit, veggies, nuts, dried beans, meats, and even prepackaged/manufactured foods.
Food poisoning is not limited to just "raw" anymore.
Most of us grew up getting sick from things when we were little, without our parents obsessing over pumping us full of anti-biotics and such, which would have dulled our immune systems to not cope with eating something like raw eggs.
Today, most kids are pumped full of anti-biotics from the day they are born, resulting in low immune systems and intolerant immune responses to outside germs and viruses.
If your kids have never been sick in their lives, then yes, I would not be allowing something like licking the spoons with anything that contains "raw" ingredients. If they have never been sick, then more than likely their immune systems would be incapable of handling something like this if they are not used to it.
Then again, 3 eggs mixed into a cake batter would be diluted to some extent, and that little bit would more than likely be rendered useless by their stomach acid.
I've never known anyone or anyone with kids, who got sick from licking the spoon.
But thats just me.