The trick to turning sweetened condensed canned milk into whipped cream is chilling the equipment that's used to beat the milk into cream. While whipping the milk, sit the bowl in an ice water bath to keep it cold. It doesn't hurt to turn on the air conditioning or whip the cream in front of an open window with a breeze, because the cold helps the fat globules in the milk stick to the air bubbles that are created when the cream is whisked, giving it its foamy texture.
Pour 1 cup sweetened condensed canned milk into a deep, narrow metal bowl and sit it in a freezer for 30 minutes.
Place the beaters to an electric blender in the freezer for 30 minutes.
Fill a large mixing bowl halfway with cold water and ice.
Check that the beaters, bowl and milk are completely chilled, then remove them from the freezer.
Sit the metal bowl in the large mixing bowl. If the water comes close to the metal bowl's edge, dump some of the water out. (This will prevent it from sloshing into the cream while you beat it.)
Whip the milk with the blender and chilled beaters on low speed for about 30 seconds or until small bubbles start appearing.
Change the blender's speed to medium. Beat for approximately another 30 seconds or until the beaters create a trail through the thickening milk.
Put the blender's speed on high. Move it in circles around the bowl's perimeter, and bob it up and down in the bowl's center so the beaters thoroughly mix the cream. Scrape the bowl with a rubber spatula as needed to keep all the cream blended. Stop blending when peaks appear and/or the cream doubles in volume.