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)
I make this often, using 3 cups organic whole milk and 1 cup organic cane sugar in a small cheap slow cooker. I cook on high heat for an hour, stirring often, then turn it down to low for 4 - 5 hours. The trick to get it to reduce is to not put the lid securely on the pot. I put a double layer of paper towels, lay a wooden spoon or skewer toward one side of the pot and place the lid on top. There needs to be a gap under the lid, so the water can evaporate from the milk. Also, it works best with whole milk - regular or lactose free. To check progress on the reduction, put a wooden skewer in the pot and measure the amount of liquid. I use a marker to mark the stick. Then you can stick the skewer in every hour or so to measure your progress. - 05 Aug 2018 (Review from Allrecipes US | Canada)