You should have tasted the cake my mother made — it was delicious.

'should have + 过去分词' 是情态动词 should 的完成式结构。此处用于叙事修辞：说话人以 'you should have tasted' 唤起听者对过去味觉体验的想象，强调美味程度，而非表达后悔或批评。