Dutch-processed cocoa powder
- Preheat oven to 350 degress; lightly spray an 8-inch square cake pan with oil spray.
- Whisk flour, sugar and baking soda together in large bowl.
- In separate bowl, whisk cocoa and water trogether until smooth. Whisk in the mayonnaise and vanilla. Stir the mayonnaise mixture into the flour mixture until combined.
- Put into pan; smooth the top. Bake until toothpick tests clean but with a few crumbs attached, about 35-40 minutes.
- Let cool in pan on rack 1 - 2 hours May top with confectioners sugar sifted over top.