Prepare all your equipment and ingredients. Make sure everything is handy and at the ready as speed can be key. Mix sugar and cinnamon for toffee coating and set off to the side.
Set heat on stove to medium/medium high (6 or 7 for dials) and melt your butter.
Once butter is completely melted, pour in sugar, water and corn syrup and stir together thoroughly. Bring to a boil. Be sure to stir occassionally.
Once boiling, add candy thermometer to the pot. cook until temperature reaches 290° F (143° C) or Soft Crack. At 290°, pour in vanilla extract and stir.
Pour toffee onto parchment covered baking sheet and spread to evenly coat as fast (and safely) as possible.
While toffee rests in baking sheet, melt white chocolate melts according to directions. Pour onto toffee and spread. Before white chocolate sets, sprinkle cinnamon/sugar mixture evenly on top.
Optional: once white chocolate has harden, flip toffee over and repeat on other side.
Let toffee rest in fridge for 1 hour to harden.
Remove from fridge and break up into small pieces. Store in airtight container.
