Combine the flour, sugar, baking soda, baking powder, and salt in a medium bowl and set aside. In a stand mixer, whisk together the yogurt and oil until fully emulsified. Add in the vanilla and orange juice. Slowly incorporate the dry ingredients in stages, until the batter is nicely mixed without lumps. Pour the batter into your prepared pan.
For the topping, whisk together the yogurt, confectioners’ sugar, starch or arrowroot, and vanilla in a small dish, stirring until smooth. Drizzle over the batter. Microwave the marmalade for about 30 seconds, until slightly liquefied and easier to pour. Drizzle it over the batter as well. Swirl both toppings together with a knife but try not to overdo it as you may muddle the colors.