Best chocolate cake for chocolate lovers

I got this recipe online but I don't remember the site anymore. Anyway, it was my first time ever to make a chocolate cake and I must say I was very, very elated by the result. In fact, our tenant when he tasted it asked how I did it. And now he wants me to make them for his friend's daughter's birthday. So, it's really that good, otherwise, he won't recommend me.

Here's the recipe which I simplified and modified a little bit.

50g chocolate--preferrably 85%
2 scoop butter using a table spoon
3/4 cup sugar -- any type of sugar will do
1/2 cup water
1 cup flour or self-raising flour
1/4 cup milk--I used soy milk
1 egg
1/2 tsp vanilla
a pinch of salt

For the Topping

50g chocolate
1 scoop butter
3 tbsp milk
1 can condensed milk
1 tsp vanilla

Procedure

Choose a pan large enough to mix all ingredients. But don't mix them all yet.

1. Melt the butter and chocolate in a hot water and stir continuously.
   
2. When it starts to boil, take away from the stove.
3. Since I use demerara sugar and they are big granules, I also melted the sugar with the chocolate mixture.
4. Beat the egg well and put in the chocolate mix. Beat again until they blend.
   
5. Add the flour and mix well. (Note: if you are using fine sugar add it now. You don't have to melt it like I did but it's really up to you.)
6. Add baking soda and beat well until you see tiny bubbles.
7. Set the oven to 350 Degrees or Gas mark 4
   
8. Pour the mixture in a 8x8 inch baking pan and bake for about 30 minutes.
   

While waiting for the cake, do the topping.

1. Melt the chocolate and butter together until they blend.
   
2. Remove from stove and add the milk and vanilla and beat well until they are well blended.
   
3. Add the condensed milk. Beat well again until blended. Leave until needed.
4. Basically, just pour it into the cake when it's cooked and leave in the oven but switch it off this time. The heat will make the topping thicker but do not cook it.
5. Enjoy your cake.