I made this years ago and was thinking about it recently...

Wacky Cake
Serves 6 to 8

This moist cake gets even better when served with vanilla ice cream or a dollop of whipped cream.

1 1/2 cups all-purpose flour
3/4 cup sugar
1/4 cup natural cocoa powder
3/4 teaspoon baking soda
1/2 teaspoon table salt
5 tablespoons vegetable oil
1 tablespoon distilled white vinegar
1 teaspoon vanilla extract
1 cup water
Confectioners' sugar

1. Adjust oven rack to middle position and heat oven to 350 degrees. Coat 8-inch-square baking pan with nonstick cooking spray.

2. Whisk flour, sugar, cocoa, baking soda, and salt together in pan. Make 1 large and 2 small craters in dry ingredients. Add oil to large crater and vinegar and vanilla separately to remaining small craters. Pour water into pan, and mix until just a few streaks of flour remain. Immediately put pan in oven.

3. Bake until toothpick inserted in center of cake comes out with a few moist crumbs attached, about 30 minutes. Cool in pan, then dust with confectioners’ sugar. (If tightly wrapped, cake will keep for 3 days at room temperature.)