Preheat the oven to 180°C/360°F/Gas Mark 4, and arrange a baking tray onto the middle shelf.
In a small bowl, mix the olive oil, water and vanilla, then set it aside until needed.
In a large bowl sift the flour together with the baking powder, and mix well with a whisk. Add in the sugar and cocoa powder and mix well.
Slowly pour the oil+water mix into the dry ingredients, and gently mix with a whisker until combined and lump-free. You can also add a pinch of sea salt to enhance the sweetness of the cake if you want.
Spray with baking oil a 7-inch springform cake pan with loose base, although not necessary, I recommend placing a disk of parchment paper over the base. Pour in the cake batter and even the top using a spatula.
Arrange the cake pan onto the middle rack and bake in the oven for about 45 minutes, then insert a toothpick in the middle of the cake. If it comes out dry, your cake is done, otherwise continue to bake for a further 5 minutes, then check again.
Take the cake out from the oven and allow to cool completely before removing it from the pan.
Dust generously with optional confectioner sugar if you like, and serve.
US Measurements1 cup + ½ cup + 1.5 tbsp (or 1.6 cups) water⅓ cup + 1 tsp extra-virgin olive oil or vegetable oil1 tsp vanilla extract or paste2 cups + ¾ cup + 2 tbsp all-purpose flour2 tsp baking powder1 cup + 3 tbsp sugar4 tbsp cocoa powder (optional)Gluten-free Water CakeSubstitute regular flour with Dove gluten-free flour and adjust the water quantity to 420 ml. Baking tips for the best cake1. Don't forget to sift the flour! This is the only way to avoid lumps and get a super light spongy cake.2. Always pre-heat oven before baking the cake.3. Don not use the oven fan setting, simply use the conventional oven setting.4. Bake the cake in the center of the oven.5. To check if the cake is done, open the oven door only until towards the end of the baking time.How to storeThis easy vegan cake would keep well in the fridge for up to 5 days.Wrap in a cling film or store in an airtight container. This will prevent it from drying out, and from catching the smell of other foods in the fridge.