Loud cracking/creaking sound only when cycling uphill
Strangely, I have a Canyon and suffered the same creaking / clicking which developed after a couple of years of ownership. It would appear when putting power down on ie. Hills. In every examination - the noise appeared to come from the front - the chainset - and only under harder effort on hills. 

Firstly, you need to look at and consider the obvious.


pedals - smooth with no play?
bottom bracket - is it worn?
crank fastening bolt(s) - is the top hat on tightly? and the non drive side fastening bolts (for Shimano) tight?


Then consider the not so obvious.
And consider noise to be caused by the tiniest amount of movement between the cranks where the main force is being applied - all the way back to and through the rear axle.

So starting at the front end with the cranks...


chainring bolts. Make sure they are tight and have a decent amount of thread on them. 3rd party alloy chainring bolts often minimalise the amount of thread.
quick release levers. Are they on tight enough? Lightweight 3rd party skewers can be a little flimsy on the clamp and tiny movements on the axle can cause noise. Try using a Shimano one for instance - and see if the noise subsides.
cassette. Is it wobbling on the the freehub? If it is - check the lockring. If the lockring is tight - then your freehub might be worn.
rear derrailleur - is the rear mech fastened tightly to the frame?
rear derrailleur hanger - has this loosened over time?
(this happened to be my issue!)
The tiny allen key fastenings bolting the replaceable hanger to the frame can come loose. As was the case in my problem.
Amazingly, the tiny movements from the rear mech hanger - caused the noises at the front of my bike. It took me many months to work this out - and in this time I stripped down the chainset at least twice and needlessly replaced the bottom bracket.


Best of luck in your hunt.