Take one can of sweetened condensed milk. Remove the wrapper. Depending on the size of your pressure cooker and the amount of dulce de leche you want to make, you can most likely cook four cans at one time.
Place the can inside the pressure cooker bowl. Completely cover with water. Cover and set the pressure cooker to high-pressure cooking, for 35 minutes.
Allow all of the air to be released and keep the can(s) inside of the machine until it has cooled for at least an hour.
Open the pressure cooker and take the cans out only when it is completely safe and the water is not too hot to do so.
I like to allow the cans to come to room temperature before opening them and using them. Spoon out and smooth out. There will be no lumps. You can put this directly into a piping bag, spread directly onto cakes, or take it by the spoon and dive-in as it is.
The dulce de leche is good to keep unopened through the expiration date on your can. Once opened, cover and put any extras into a sealed container and refrigerate for up to four days.