Step 1

Butter an 8-inch square pan, or for thicker caramels, a 9x5 inch loaf pan. If you like, you can then line the buttered pan with foil and butter the foil.

Step 2

Melt butter in a large microwaveable bowl (microwave for about 1 minute).

Step 3

Stir in the corn syrup, both sugars and sweetened condensed milk. Continue stirring until most of the sugar is dissolved.

Step 4

Microwave on high for 3 minutes and 5 to 15 seconds. ( I recommend starting with the shorter time of 3 minutes 5 seconds, since I'd rather have my caramels too soft than too hard). Remove from microwave and stir and scrape down the sides of the bowl.

Step 5

Return to microwave and cook on high for another 3 minutes and 5 to 15 seconds. Stir in the vanilla. Pour immediately into the buttered dish.

Step 6

Allow to sit for several hours until cooled and set. Cut into squares and wrap in waxed paper.