My two doors down neighbor R, a transplanted Argentinian in Seattle, told me a couple weeks ago --when I asked her about her favorite Dulce De Leche brand-- that even when she knows how to make it from scratch (milk, sugar, vanilla and baking soda) her preferred method for cooking it was "boiling the can of condensed milk for a few hours".
The other day, to make use of some of the "homemade" (ha ha!) Dulce De Leche I whipped up last Thursday, Mr. C cooked us a little breakfast using the Flappin' Jack Pancake Mix he likes so well. After the flapjacks were ready he topped his with dulce while I rolled mine. They were both quite delicious.
Quick Dulce De Leche
1 can Eagle Brand Condensed Milk
Remove the label from a can of condensed milk and place in a kitchen towel lined large saucepan. Fill pan with cold water. Let water come to a rolling boil for one minute and then gently simmer for the next 3 hours while making sure can is covered in water at all times. After cooking time ends, let the can cool before opening and empty contents in sterile jar.