We already showed you:

$hash{$_} = { %$value } for @keys;

or

$hash{$_} = { %value } for @keys;

The only concise alternative which comes to mind is

@hash{ @keys } = map { { %value } } @keys

But it's neither shorter nor easier to read.

Cheers Rolf

update

But honestly you should stick to syntax you understand, even if it takes some lines more.