Preheat oven to 350ºF (180ºC or gas mark 4).With a mixer; beat applesauce, water, oil, vanilla, cocoa and sugar until smooth.
Add flour, salt and baking powder and mix until well combined. Stir in chocolate chips.Spoon batter onto a lightly greased 11x17x1-inch jelly roll pan.
Bake for 7 minutes, rotate the pan and bake for an additional 9 minutes.
Let cool completely, then cut with Halloween cookie cutters.
Sprinkle granulated sugar and anything else, including powdered sugar, safe candies or candy pieces, to make the treat your own.