If you want to really move beyond the kit thing, instead of "adding sugar", use dried malt extract (aka "DME"). You'll appreciate the improvement.
Also, if the can of malt is hopped, you don't want to boil that for much more than 5-10 minutes, lest you remove its hop content from the aroma (first to go) and flavor (next to go) characters.
If you go with both the above suggestions, start your boil with the full amount of water for your batch size, plus the DME. Get it boiling then add some of the Cascades and boil for 10-15 minutes, then add the canned malt and the rest of the Cascades and boil for another 10 minutes, then start the cool down towards pitching temperature...