in a saucepan, place butter, water and sugars
set aside the baking soda and pure vanilla extract
At medium heat, start to melt these ingredients in your pan.
Place a candy thermometer into the mixture. You'll keep close and watch as the mixture comes to 300 degrees Fahrenheit or 150 degrees Celsius.
As soon as it hits temperature, remove from heat.
Stir in baking soda and vanilla
The end result will be smooth and with a lot of air in it.
Pour over ingredients.
If plain, pour down directly onto the parchment paper in one pool of toffee.
Cover the poured toffee with one cup of chocolate chips.
Let the chocolate chips sit for two-five minutes.
Use a slotted spatula spread-in the chocolate.
Cover the toffee with the chocolate chips.
Let the chocolate cool and set completely. It will be dry and crisp. This could take up to an hour or more, depending on the humidity in the room.
Use your hands to break up the slab into pieces of bark. You are set! The chocolate is re-tempered and will not smudge. This dessert is basically candy, so it can be stored at room temperature, in a sealed container, for up to two weeks.