Grease and line the bottom of a 7 inch (18 cm) round cake pan. Set aside.

Melt the chocolate in microwave with 30 seconds intervals and mix well after each interval. Set aside.

Sift flour, baking powder and salt into a bowl. Set aside.

In another bowl, add in butter, sugar and oil. Whisk until well combined and very creamy. Then add in vanilla extract and the eggs, adding the egg 1 by 1 and mixing well after each addition. Finally add in coconut milk while still mixing.

Now add in the sifted flour mixture in 2 additions, mixing just to combine after each addition. Don't over mix to avoid hard dense cake.

Separate half of the batter into another bowl. Add in previously melted chocolate into one batter and immediately fold everything to combine. Don't over mix.

Spoon 1 tablespoon of vanilla batter to the center of prepared pan. Then spoon 1 tablespoon of chocolate batter in the center of the vanilla batter. Keep repeating until you finish the rest of the batter, reducing the amount of tablespoon as the both batters are finishing. Give the pan a gentle wiggle as you go to help the batters settle in.

Bake in a preheated oven at 320ºF (160ºC) for 50 minutes or until fully cooked. Remove from the oven and cool completely on a rack before slicing. Enjoy!