See OC164. Mishne Brura #39 ( it’s a long one…about in the middle)
Does it make a difference Shabbos or Chol
Does it make a difference if you had wine during the meal( either Kiddush or just a glass of wine)
If you dont make a bracha shehakol, why do you otherwise make a bracha on any other part of dessert?
Abie