Ignorant gwai lo buys unknown food!

I wonder what this is? It certainly looks good!

One of the joys of being in a new country is to be able to try new foods. This is slightly complicated by being a vegetarian, but I try not to let that hold me back. There are so many interesting things being sold at the moment in honour of Chinese New Year, and I am curious about nearly all of them.
Today, as I was shopping in one of the wet markets in Tai Po, this little thing caught my eye. I handed over the cash and continued with my shopping. When I got home, I dove into the choppy waters of the internet to try and find out what it was I'd purchased. No luck! Nowhere on Google™ images, or indeed anywhere I stumbled upon, contained pictures or a description of what I had bought. I googled desserts/cakes/sweets, because I thought it was a sweet, I googled red, and sesame seeds, and chrysanthemum, because that is what the decoration resembled. Nothing, nada, 莫!

All that was left to try was to actually eat it. Now why didn't I try that first? Inside there turned out to be a sort-of peanut-brittle mixture, with a very hard and crunchy texture, not too sweet, with a pleasantly nutty taste. I couldn't work out what the outside was, perhaps a rice flour shell, who knows?
So I am left with a bit of mystery. When do these things traditionally get eaten? What are they called, in Cantonese, or English? Do they signify anything important? Are they supposed to be eaten by the young, the old, the single or the enspoused, or can anyone eat them? So many questions... If anyone has any ideas or clues about these, I'd love to know more. There seem to be dozens of traditional sweets at New Year, but I still don't know which category these fit into.