Step 1Heat the oven to 350 degrees. In an 8-inch-square baking dish, sift together the flour, sugar, cocoa, baking powder and salt. Smooth out the powder. Then, using the handle of a wooden spoon, poke two small holes and one large hole in the dry ingredients. Put the vinegar in one small hole and the vanilla in the other. Pour the oil into the large hole. (It will overflow, not a problem.)
Step 2Pour the cold water or coffee all over the top. Then use the wooden spoon and stir well to blend all of the ingredients together until smooth.
Step 3Bake until a toothpick inserted in the center comes out clean, about 25 to 30 minutes.
Step 4When the cake is completely cool, top with your favorite icing or sprinkle on powdered sugar. It is also nice with berries and whipped cream or ice cream. (Or you can skip any topping and instead add three-fourths cup of chocolate chips as you stir the mixture.)
Step 1On a low speed of an electric mixer, beat the cream cheese and sugar until soft. Beat in 2 tablespoons of the cream and then the vanilla. If the frosting is too thick, add more cream, 1 tablespoon at a time, until it is the right consistency for spreading.
Step 2Wait until the cake is completely cool before frosting and then store it in the refrigerator.