Grease an 8x8-inch pan or line with parchment paper.
In a large microwave-safe bowl, combine butter, white sugar, brown sugar, corn syrup, and sweetened condensed milk.
Microwave on high for 6 minutes, stirring every 2 minutes. The mixture should bubble and thicken slightly.
Carefully remove the bowl (it will be hot) and stir in the vanilla extract.
Pour the caramel mixture into the prepared pan and let it cool completely at room temperature.
Once set, cut into squares and wrap individually in wax paper if desired.