Preheat the oven to 400°F, and line a 15 x 10-inch baking sheet with foil. Lightly spray the foil with cooking spray. Place the crackers in an even layer on the baking sheet. Set aside.

In a medium saucepan, combine the butter and brown sugar over medium heat. Stir the mixture until it comes to a full boil, then stop stirring for 2 to 3 minutes. A candy thermometer should read between 270° and 290°F when inserted into the mixture.

Carefully pour the toffee over the crackers, and use a spatula to spread it evenly over the crackers. Place the crackers in the oven and bake for 5 minutes. The toffee should begin to bubble.

Remove the toffee from the oven, and sprinkle with chocolate chips. Allow the candy to set for 3 to 4 minutes until the chocolate chips have softened. Use a spatula to smooth them over the toffee.

Sprinkle with chopped nuts and holiday sprinkles (or do half and half). Refrigerate for 30 minutes to an hour to allow the toffee and chocolate to set. Then, remove from the refrigerator, and break the toffee into pieces.

Store in an airtight container for up to 5 days.