Preheat oven to 350 degrees. Butter and flour an 8-inch diameter cake pan.

Sift the flour, baking powder, baking soda, and salt into a large bowl. Add the sugar and cardamom and whisk everything together. Set the bowl aside.
In a medium-size bowl mix the yogurt, eggs, and olive oil. Gradually add the wet ingredients to the dry ingredients and combine with a spatula or wooden spoon. Be careful not to over mix. Add the orange and lemon zest and juice. Gently fold everything together and pour into the prepared baking pan. Bake for 40 to 45 minutes, until the cake is done. You can test this by inserting a toothpick into the center. If the toothpick comes out clean the cake is done.
Leave the cake to cool completely before icing.
Combine powdered sugar with the juice from the leftover orange. Mix together until you have the right consistency (not too runny, not too thick) you can adjust by adding more powdered sugar or orange juice as needed. Spread onto the top of the cake and enjoy.