Preheat oven to 180°C (350°F).

Prepare a 5-inch round pan or a 9-inch loaf pan.

Sieve together all-purpose flour, whole wheat flour, baking powder, baking soda, and salt in a mixing bowl.

Set the dry ingredients aside.

In a separate mixing bowl, beat the eggs until fluffy.

Add sugar, oil, marmalade, and orange juice to the beaten eggs and whisk until well blended.

Gently fold the dry ingredients into the wet ingredients, alternating with buttermilk.

Pour the batter into the prepared pan.

Bake for 30-35 minutes, or until a cake tester inserted into the center comes out clean.

Let the cake cool in the pan for 5 minutes.

Invert the cake onto a cooling rack and allow it to cool completely.

Drizzle warm marmalade over the cake.

Serve with a hot beverage.