Even though the Luftwaffe lacked a heavy bomber force similar to the Allies, it nevertheless did attempt several sporadic strategic bombing campaigns during the War; often of limited duration.
The ones I know of are:
The Blitz, 1940/1.
Malta, 1941/2.
Moscow, 1941/2.
Volga, 1943.
Baedeker Blitz, 1942/4.
Have I missed any?
Luftwaffe Strategic Bombing.
Re: Luftwaffe Strategic Bombing.
Tip-and-Run Raids, Baby Blitz.