Combine corn syrup, water and sugar in pot on top of stove on low heat.
Stir till sugar has completely dissolved.
Once sugar has dissolved, cook without stirring to hard ball stage - 265 degrees.
Add salt and butter and continue to brittle stage - 300 degrees (if you are using the iced water method to check for candy stage, brittle stage is when you pour a little of the mixture into the water, it creates threads that easily break when you pull it out of the water)
While this mixture is cooking on stove, toast up shredded coconut in oven on cookie sheet. Take out and let cool.
Remove brittle mixture from heat, carefully add coconut and vanilla extract and stir till combined.
Next, grease up cookie sheet with butter, an pour brittle mixture into cookie sheet.
When cool enough to handle brittle, take by the edges and stretch into a thin sheet.
When brittle is completely cooled, break it up into irregular pieces.
You can also add toasted or even roasted chopped mixed nuts or just one type of nut like cashews for an amazing extra flavor!
Makes 1 pound.