If you store the BitLocker recovery key with the cloud domain account when you encrypt the laptop (see below), you can find it in Azure AD.
To find the recovery key:
1. Log into Azure AD (https://manage.windowsazure.com)
2. Under the Manage heading , click Users
3. Search for the user and click on their name
4. Under the Manage heading, click Devices
5. Click the name of the device
6. Towards the bottom, you will find the key