Preheat and Prepare Pan: Preheat oven to 350°F (177°C). Line an 8×8 inch square baking pan with parchment paper, leaving an overhang on two sides to use as “handles.”

Mix Dry Ingredients: In a large mixing bowl, add the self-rising flour and unsweetened cocoa powder. Mix on low speed (or whisk by hand) until evenly combined and there are no clumps.

Add Sugar, Water, and Oil: Add the granulated sugar to the flour mixture and mix on low until combined. Pour in the water and vegetable or canola oil.

Create the Batter: Turn the mixer to medium-high speed. Beat the batter for about 1-2 minutes, or until it is perfectly smooth and glossy. Scrape down the sides of the bowl as needed.

Pour and Bake: Pour the batter into the prepared 8×8 cake pan. Bake for about 30 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool the Cake: Let the cake cool in the pan on a wire rack for 15-20 minutes. Then, use the parchment paper handles to lift the cake out. Let it cool completely on the rack before frosting or cutting.