Grease sides and bottom of round cake pan (7 inch, 18 cm diameter). Line bottom of pan with parchment paper. Set aside.
Preheat oven to 350oF (180oC).
To a bowl, add sugar, cocoa powder and water. Mix until sugar dissolves completely. Then, add oil and lemon/white vinegar and mix.
Sift in flour, baking powder and baking soda.
Mix until dry flour is no longer visible. DO NOT OVER MIX (mix until dry and wet ingredients are just combined).
Transfer batter to prepared cake pan.
Bake in preheated oven at 350oF (180oC) for 30 minutes (for a fudgy texture) or 35 minutes (for a more cakey texture) , or until toothpick inserted in the middle of cake comes out clean.
Let cake cool down for 5-10 minutes in pan. Then, transfer to wire rack to cool down completely.
