Preheat oven to 180 degrees, prepare a baking tin with butter, flour and lining the bottom with baking paper
Sift the flour, 1/2 cup cocoa, 1 cup sugar, baking soda and salt together.
Add the wet ingredients, vegetable oil, 1/2 tsp Vanilla extract, 1 cup Hot water and white vinegar to the dry ingredients, mix well and pour into the prepared baking dish. Bake between 20-25 min until a skewer comes out clean.
In the meantime while the cake is baking prepare the syrup by mixing the hot water, cocoa, sugar and vanilla in a separate jug.
When the cake is cooked, take it out the oven, pearcing it all over with holes. Pour the syrup all over the cake, the syrup will quickly be absorb. Leave to cool completely.
Mix the powdered sugar, cocoa and caramel and spread over the cooled cake. Optional: add chopped hazelnuts