CHOCOLATE MIRROR GLAZE/Moist chocolate cake with chocolate ganache

MOIST CHOCOLATE CAKE: 1 cup All purpose flour 6 tbsp cocoa powder 1 tsp baking powder 1 tsp baking soda 1 cup fine white sugar ½ tsp salt 1 medium egg (room temp) ¼ cup sunflower oil (veg oil) ½ cup buttermilk(milk 1 ½ tsp vinegar) 1 tsp vanilla extract ½ cup hot water 1 tsp coffee CHOCOLATE GANACHE: 300 grm dark chocolate or semi sweet or combination 150 grm whipping cream (or all purpose cream) CHOCOLATE MIRROR GLAZE: 2 ½ Tbsp water 4 tsp gelatine powder 1cup cocoa powdee ⅔ cup water ⅔ cup whipping cream 1 cup white fine sugar Glaze recipe adapted from Recipetin Note: Baked the cake 1 day ahead and chill in the fridge. On the next day I make the glaze first since it needs 2 to 3 hours to cooldown(room temp only). Then I make the chocolate ganache, I let it sit at room temp for about 30min.,then put in the fridge for 30 minutes. I mix it with spatula until the consistency cha