Here’s another good thread on this topic in regard to low-cadence or “torque” efforts.
Ultimately, low-cadence is low-cadence no matter if you’re going up or down. 
Here are the main points I mentioned in the above thread:
We do have a few workouts that incorporate low-cadence drills, but you could incorporate torque training into any workout that you’d like. 
If anyone isn’t familiar with these types of efforts I’d recommend starting by doing short bits of riding with your cadence slightly lower than normal during a Sweet Spot workout. You can slowly work on continuing to lower your cadence over time and then lengthening the duration of these drills as you see fit. Over time if things are feeling good you could start to build these into Threshold work and later even some VO2 Max. Again, ease into it, and be gentle at first!
Some elite cyclists have worked up to 10 minutes at 30-35rpm! 
These are great exercises to incorporate into early/off-season training alongside some gym work as they are great for building up your neuromuscular pathways. 
