Pre-heat oven at 356F/180C.
Grease the tray with some oil. The sizes of my tray are approx. 10cm x 30cm.
Separate egg yolks from the egg whites.
Whisk egg whites until foamy. Add sea salt.
Whisk egg yolks with sugar, oil, vanilla extract and baking powder. Slowly add flour and incorporate. Add foamy egg whites and dry fruits. Mix using a spatula.
Pour the composition in the greased tray.
Save 1 Tbsp of the batter and put it in a small bowl. Add cocoa and mix.
Pour this over the batter in the sweet bread tray. You can make the swirls on top using a teaspoon. Press it just a little.
Put it in the oven and let it bake for 35 minutes.