Setter will have American pie sent over at four, for sweetheart - this is typical (12)

'typical' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I don't see?

'setter will have american pie sent over at four for sweetheart' is the wordplay.
I cannot quite see how this works, but
'setter' could be 'i' (the person who set this crossword) and 'i' is found in the answer.
'will' could be 'll' (contracted form, as in 'he'll' - 'he will') and 'll' is located in the answer.
'american' could be 'us' (United States) and 'us' is found within the answer.
'at' is present in the answer.
'four' could be 'iv' (Roman numerals for four) and 'iv' is present in the answer.
'over' could be 're' and 're' is located in the remaining letters.
A single letter 't' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...

'this is' is the link.

Can you help me to learn more?