Gaucho Sam said:Mini, you can do it with actual milk as well though, which is what I assume bajo_cero 2 means, since she talks about using milk to make it. You heat it up on the stove with some brown sugar or something, but I'll let BC2 explain because the one time I tried it (with some help from my Argentine then-girlfriend!) it got very, very messy indeed. A hint: if you don't get it just right, you may have to buy a new saucepan.
Yes, I know how to make dulce de leche in a sauce pan with "actual" milk. Condensed milk is milk BTW with the sugar already in it & as was said above you don't have to worry about the milk being watery as Bajo mentioned. If you do it in the can you don't have to stir anything or make sure it sticks to the pan or burns, etc. There is nothing easier than putting a can in a BIG pot of water, check every a few times that the water hasn't evaporated & done.