fruit cake 
noun
1A cake containing dried fruit and nuts: a rich, moist fruit cake [mass noun]: Ella filled her mouth with fruit cake...
- Both staff and residents alike enjoyed a sample of the tier of the wedding cake which was a rich fruit cake.
- When Donna graduated from college, she became a food stylist at a time when a sheaf of wheat, a spray of carnations and a patterned plate were required to accessorise a fruit cake for photography.
- By the way, a bite of the pretty white cake made me not want to eat any more sweet stuff on Christmas day, I ate my fruit cake on the next day.
2 (fruitcake) informal An eccentric or mad person.Will you meet nutcases and fruitcakes in your travels?...
- That he was loathsome, a complete fruitcake, and madman is well known.
- A while ago I suggested that it would be a good idea for Americans if they were to hive off a part of the country I call the ‘axis of stupidity’, and let all the fruitcakes who have been dragging the whole country down go live there.
Compare with nutty as a fruitcake (see nutty)