1/4 pound (1 stick) salted butter, plus extra for buttering the pan
One (14-ounce) can sweetened condensed milk
2 cups granulated white sugar
1 1/2 cups light corn syrup
1 teaspoon vanilla extract
Butter a 9x13-inch pan.
Melt the butter in a heavy saucepan over medium heat. Add milk, sugar and syrup. Stir continuously with a wooden spoon until a candy thermometer reaches 240 degrees F. Take off heat immediately. Stir in vanilla.
Pour into your prepared pan. Cool in the refrigerator until firm. Pop caramel block onto a cutting board. Cut into 2-inch cubes and wrap each caramel in waxed paper.