Mix and sift in the flour, cocoa and baking powder.
Add the rest of the ingredients and whisk with an electric mixer for about 2 minutes.
Bake for 40 minutes or until the cake is springy to the touch and a when tested with a knife or skewer it comes out clean.
Allow the cake to cool in the tin for 5 minutes before transferring it to a wire rack.
Mix together 3 drops of wild orange essential oil and caster sugar and drizzel over the top of the cake.
When the topping has set cut the cake into slices and enjoy your citrus creation.
Alternatively if you are feeling more creative swap out the caster sugar and water for whipped cream and add some orange peel and slices for decoration and extra zest!