It sounds like your brothers are big fans of the song "Toast" by Koffee, a Jamaican reggae artist!

As for the lyrics you mentioned, it seems like there's a clever play on words going on - the phrase "Those doughnuts have great taste" is a humorous reference to the idea that they're enjoying the song (with its catchy title) rather than actual doughnuts.

It's also cute that your little brother got you into Koffee's music! Do you enjoy her songs as well?