Three ingredients are all you need to make sweetened condensed milk in your slow cooker. Don't worry about it not being thick enough when you finish cooking - it will get twice as thick as it cools. It'll last about 2 weeks in the fridge or 3 months in the freezer.
I make my own french vanilla creamer for coffee. I ran out of cond milk and decided to try this out. Way better than the canned stuff! I did end up cooking it 5 hours in my little crockpot, but it's so nice to pour everything in and let it go. Goodbye cans! edited to add: I did use 2% milk which may be why it needed to cook longer - 22 Jan 2016 (Review from Allrecipes US | Canada)
This turned out way better then I thought before it cooled. I must say I used this in my coffee this morning and can't wait to try it in other things. It is thick and cream with a wonderful flavor. The time it took to make this was well worth it. - 14 Nov 2015 (Review from Allrecipes US | Canada)
Didn't thicken after 4 hours in crockpot. Butter separted from finished prpduct. Used 2% since recipe did not specify so this may have been a factor. Did well as coffee creamer. - 12 Dec 2017 (Review from Allrecipes US | Canada)