Preheat your oven to 350 degrees Fahrenheit, and line a large baking sheet with parchment paper.
Line the baking sheet with saltine crackers and set aside.
In a medium sauce pan, combine the brown sugar and butter. Cook over medium-high, until butter melts and mixture begins to simmer.
Simmer for about 5 minutes.
Pour the sugar and butter mixture over top of the saltines evenly.
Bake in the oven for about 5 minutes. Sugar and butter will be bubbling.
When you remove the pan from the oven, quickly sprinkle white chocolate chips over top.
Allow a minute or two for the chocolate chips to begin to melt, and smooth the chocolate out evenly over the crackers and toffee.
Sprinkle with green sanding sugar.
Use the cookie icing to draw the lines across your bark to make it resemble Christmas Tree Cakes!