I know absolutely nothing about Laravel and haven't touched PHP in nearly 20 years - but within about 10 seconds on Google I found the following, which at first glance looks pretty comprehensive:
That is an old version, the current being https://laravel.com/api/6.x/ but I have to agree, I have found them to be great. There is no reference to the API docs from the main website though, which I have always found odd.
https://laravel.com/api/4.2/