Not sure if a post like this exists already but this is a dead-easy cake to make, super soft, moist and can be "customized" to taste... The super strict vegan might wanna lay off the rum though...
Ingredients for the cake:
6 tablespoons cocoa powder (pure, no sugar)
2 teaspoons baking powder
2 teaspoons bicarbonate of soda
450 g / 15.8 oz. flour
300/350 g / 10.6 / 12.3 oz. sugar (depending on how much of a sweet-tooth you are!)
125 ml / half a cup vegetable oil
300 ml / 1 1/4 cup water
2 tablespoons white vinegar
2 teaspoons vanilla extract
1 jar of jam
Rhum (when possible Stroh Rum 80%)
For the cake:
Preheat the oven at 180 C (about 360 Fahrenheit)
I use brown sugar but blitz it before use so it's fine, kinda like caster sugar. Sift all the dry ingredients and mix them with the sugar.
Combine the wet ingredients in a separate bowl and stir a bit, then pour them into the dry ingredients and stir or beat until it gets all smooth.
Grease the cake tin (I use a springform, makes it easier to get the cake out limiting the damage...) and pour the mix. I usually bake it for 50 minutes, check with a wooden toothpick if you don't trust your oven (like I do...).
Take the cake out of the oven and let it cool down. Once it's settled, remove the springform, slice the cake in half, sprinkle both halves with a bit of rum, fill the middle with whatever jam or cream you like. I usually go for cherrie jam spiked with a bit of rum, it takes off the super sweet edge of some jams and gives it the extra kick

For the icing:
(taken from Easy Vegan Cooking)
55g / 1.9 oz veggie margarine
30g / 1 oz cocoa powder
4 tablespoons of soy milk
140g / 4.9 oz brown sugar
1 teaspoon vanilla essence
Combine the first four ingredients in a saucepan and bring them to the boil slowly, stirring constantly.
Boil for one minute.
Remove from the heat and beat until cold. Add the vanilla essence and spread the icing on the cake.
For both the cake, and the icing I always add a little bag of vanilla sugar or vanilla essence, but that is an extra...