How to access / include a custom Blueprint from within a C++ class?

I have a custom Blueprint named “BP_Sky”. This contains a variable which I want to access from a C++ class (or rather an actor of that class). How can I access this BP_Sky blueprint (object)?

In the standard C++ I’d just include the header file, but if there is such a thing for the blueprint, I don’t know where to find it / where to point the include command to.

AMainGameMode::AMainGameMode()
{
static ConstructorHelpers::FClassFinder PlayerPawnClassFinder(TEXT(“/Game/Blueprints/BP_MainCharacter”));
DefaultPawnClass = PlayerPawnClassFinder.Class;
}

Use the FClassFinder with construction helpers within the constructor of your C++ class.