Cup of Yum
1. Place the zested oranges (without their zest) in a large saucepan and cover with water until submerged. Place on medium heat and boil for 2-2.5 hours or until oranges are very tender when poked.
2. Cool slightly and cut each orange in half so you can remove the pips. Blend the oranges until they turn into a pulp (you could also use the large side of a box grater to do this). Fold in the orange zest, and set aside.
3. In a separate bowl, whisk the baking powder thoroughly with the almond flour. Set aside.
4. In the bowl of a mixer, add the caster sugar and eggs and whisk on medium speed for 2-3 minutes until light and foamy.
5. Add the orange mixture to the egg and sugar mixture and fold gently to combine. Add the almond flour mix to this, and fold to combine.
6. Pour into a prepared 9x13 baking pan. Sprinkle with flaked almonds if using, and bake for 30-35 minutes or until a toothpick comes out clean. Cool completely.

For the glaze:

Cup of Yum
1. In a sauté pan over medium heat, add the marmalade and the water. Stir until marmalade has melted and let it simmer for a minute or so. That's the glaze! Brush glaze onto cooled cake.