A strong and happy memory I have from childhood is making sweets with my Dad. Sweet rationing had ended before I was born, but we still didn’t have many and what we did have were of the Cadbury’s chocolate and Mars bar type. Not a whole Mars bar. They were huge. Dad would cut one up bitesize and share it round.
I longed for fizzy sweets like flying saucers and love hearts. I remember being given some money and spending it on a lucky bag and other questionable fizzers. My Dad threw the lot on the fire as a never forgotten (though probably deliberately misleading) example of those type of sweets being just made up of chemicals … hence the multitude of colours as they burned. Whether it was scientifically true or not, it worked and I’ve never wanted those kind of sweets since.
We then had a massively messy sweet making session. Fudge, toffee apples, coconut pyramids and most fun of all the sort of honeycomb you get in crunchie bars. I can’t remember what was in them - and they probably involved lots of sugar and ither things that would have been rationed on VE Day (though I expect ration books were pooled or ignored). The honeycomb was spectacular as we added bicarbonate of soda or some such and everything just grew and grew and kept on expanding, over the top of the saucepan and down the front of the stove onto the kitchen floor where I trod in it.
There are bound to be wartime sweet recipes on line and @Pauline could probably tell you more about vintage sweets. Your son might enjoy doing something like that, if you have some ingredients and don’t mind the mess.