Spray an 8-inch baking pan with nonstick cooking spray. Pre-heat the oven to 350°F.
Place a sifter over the the prepared pan and sift together the dry ingredients (flour through baking soda). Shake the pan slightly to even out the dry ingredients and, using the end of a wooden spoon, poke three holes in the dry mixture. Measure the oil in one hole, the vinegar in another and the vanilla in the third. Pour the water carefully over the ingredients in the pan and mix gently until all lumps are gone – remember to get the corners. Add the chocolate chips and stir briefly to combine.
Bake the cake for 28-38 minutes, or until a cake tester just comes out clean. Serve frosted, topped with powdered sugar or straight up.