1 can sweetened condensed milk

Empty milk can into a slow cooker. Cover and cook on low for 7 to 8 hours until milk is rich, caramel color, stirring every 45 minutes to an hour.

Here are a couple of other methods for making it.

Oven method: Pour 1 can sweetened condensed milk into 9-inch pie plate. Cover with aluminum foil; place in a larger shallow pan. Fill larger pan with hot water. Bake at 425 for 1 hour or until thick and caramel-colored. Beat until smooth.

Stovetop method: Pour 1 can sweetened condensed milk into top of double boiler; place over boiling water. Over low heat, simmer 1 to 1d hours, or until thick and caramel colored, stirring occasionally. Beat until smooth.

Microwave method: Pour 1 can sweetened condensed milk into 2-quart glass measuring cup. Cook on 50 percent power (medium) 4 minutes, stirring briskly every 2 minutes until smooth. Cook on 30 percent power (medium low) 20 to 25 minutes or until very thick and caramel colored, stirring briskly every 4 minutes, during the first 16 minutes and every 2 minutes during the last 4 to 10 minutes.

Source: Eagle Brand Condensed Milk.