Preheat oven to 160 degree c.
Line two 8 inch cake pan with parchment paper. Grease it well with oil.
Take flour, cocoa powder, baking powder, baking soda, salt in a bowl and mix well.
Take egg, sugar, brown sugar, oil, vanilla, curd and mix well.
Add in flour mix and hot coffee and mix well.
Pour it into the cake pan and bake for 25 mins.
Remove and cool completely.
Start by making buttercream.
Take soft butter in a bowl and whip till creamy.
Add in half of the icing sugar and mix well till creamy.
Add in remaining icing sugar, cocoa powder and mix well till it gets crumbly like wet sand.
Add in cream and whip till creamy and fluffy.
Add vanilla and mix well.
Unmould cake in a cake stand.
Spread buttercream and spread. Place another cake over it.
Spread with buttercream evenly.
Decorate as per wish.
Set the cake for 30 mins in fridge.
Slice and serve.