Preheat oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil.
Arrange crackers onto the prepared baking sheet.
Stir butter and sugar together in a bowl until the sugar dissolves; drizzle over the crackers.
Bake crackers in preheated oven until golden brown, about 10 minutes.
Spread chocolate chips over the crackers to cover completely immediately after removing the baking sheet from the oven, allowing the residual heat to melt the chocolate. Sprinkle nuts over the chocolate layer before it re-solidifies.
Cool the bark to room temperature. Once the chocolate is again firm, break the sheet into pieces to resemble tree bark.