Here are a couple of fun crocheted cupcake pincushions I recently finished. This is the first one I made. It is made with baby or sport yarn for the cupcake part, and worsted weight for the "frosting". This one did not have you joining the rounds. I really didn't care for this pattern, but I made two of them and gave one away.
I do like the size of this cupcake and the way it is weighted with beans, though, and also the way the "frosting" looks as if it is sort of dripping down. Here's the link if anyone wants to try this one:
crocheted cupcake pincushion
And then I went in search of a different pattern. There are a surprising number of them out there. I like this pattern much better; it was far more user-friendly in spite of the fact that the first one was apparently geared to children. This pattern does have you joining rounds, and it uses worsted-weight yarn for the entire cupcake.
Notice the cute little swirly peak at the center top of the "frosting". It does come out quite large, however. Here's the link for this one if you'd like to try it.
another crocheted cupcake pincushion
(The above site also has a crocheted pincushion which resembles a chocolate donut with white frosting and sprinkles. Cute!)
The upshot of my cupcake experiment is that I wasn't totally pleased with either one. My thought had been to crochet a few of these to keep on hand for little gifts, but I abandoned that plan. The cupcakes are going to my little granddaughter to add to her play food collection, so it isn't a wasted effort. Meanwhile I will continue my search for the perfect crocheted cupcake "recipe"!