Dulce de leche is a creamy caramel sauce that's traditionally made by simmering a pot of milk and sugar, stirring as you go, for seven hours. You could do that, or you could do what is by far the easiest way to make it: simmer a closed can of sweetened condensed milk in a pot of water for two to three hours (I should know, because I've tested just about every method I've come across.)
Before I go through the insanely easy steps for making dulce de leche this way, I have just one important warning: You must pay attention to the water level in the pot as the can simmers. If you let too much water evaporate and the can ends up not being fully submerged, it can overheat, tear or even explode, which would be bad.
That one detail in mind, here's how it's done...
Step 1: Remove the Label
The first thing you'll need to do is get yourself a can of sweetened condensed milk and remove the label.
Step 2: Place the Can in a Large Pot
Place the can on its side in a large pot, like a soup pot or Dutch oven. If you place it right-side up, the simmering water will cause the can to bounce as it cooks, which can be quite annoying to a sensitive baker's ears.
Step 3: Fill the Pan With Water
Add room temperature water, filling the pot until the water level rises at least two inches above the top of the can. It's very important that the can is completely submerged!
Ideally, the water level should never get any lower than one inch above the can as it cooks, so make sure to check on the water level every half hour and be ready to add more boiling water as needed.
Step 4: Simmer
Place the pot over high heat and allow it to come to a simmer. Simmer the can for two to three hours, depending on how dark you want the dulce de leche to be. The dulce de leche in the photo above was cooked for two hours.
When the time is up, carefully remove the can from the hot water using a pair of tongs and allow it to cool to room temperature on a wire rack. Do not attempt to open the can while it's still hot, as the hot dulce de leche may spit out because of the pressure inside the can. The dulce de leche will firm up as it cools, but once out of the can, it can easily be reheated in a double boiler to a spreadable or drizzle-able consistency.
Dulce de leche is delicious straight out of the can (spoon optional), but you can also serve it over ice cream or use it as a filling for cakes or cookies. Personally, I really enjoy baking with it, and I've made amazing treats and desserts ranging from Dulce de Leche Chocolate Chip Cookies to Dulce de Leche Ripple Ice Cream with Salted Macademias, Dulce de Leche Cake, and cookies stuffed with it. It's just delicious!