I posted my vanilla cake previously.

For the chocolate cake: stir together sugar, flour, baking powder, salt and cocoa powder in a large bowl

Add eggs, milk, melted butter and flavour. Beat on medium speed on mixer for 2mins.

Add n mix with boiled water(batter till its thin), pour the batter into prepared pan and bake for 30 to 35mins

I used butter cream for the frosting.