So not a bad start. Some of this was probably the easiest. The biggest challenge was getting the icing to wrap around the donut without clipping. I had a lot of fun personalizing the drips. On the inside of the donut I made some of the icing crease. It doesn't show up that strongly.
Coloring the donut and icing was a pretty good time. I made the icing as shiny as possible. Really shows off those details I did earlier. However when it came to using the geometry nodes to procedurally generate the sprinkles in the right locations I messed up. I accidentally connected the sprinkles to the donut rather than to the icing.
I was able to fix that by starting over with the geometry nodes. I took a break for some weeks after this point.
When I came back to it all, it was time to tweak and color the sprinkles with the shading tools. There was a good use of different tools to duplicate and reshape the sprinkles. There were some designs I liked, and the ones I didn't I just deleted. Then shading nodes in order to get all of the colors to vary in this way without gradient or mixing.
Not featured here I also animated the donut. The lighting I think needs to be improved. Also I don't know (yet) how to move the source-sprinkles for the geometry nodes out of the picture so that there isn't a random selection of floating sprinkles detached from the donut. I'm sure I can move them individually and attach them to the icing. If the source sprinkles are deleted, then all of their copies on the icing also disappear.