I usually use a 9-inch springform pan for this recipe. I've also used an 8-inch springform pan and ¾ cup of honey, and it comes out higher. Go with ¾ cup of honey or maple syrup for a more cake-like texture. Use 1 cup of honey or maple syrup If you prefer this cake a bit more sweet and saturated, which is how it looks in the picture with the curled orange peel.I use non-stick springform pans. If your pan is not non-stick then I recommend using parchment paper at least for the bottom of the pan.I use a blender to get the oranges pureed after they've been simmered. Then I put all the ingredients except for the egg whites in a food processor and process for a bit to get a smooth batter. I whip the egg whites until fluffy and then fold them into the batter.I separate the egg yolks and egg whites to lighten the cake and whip the egg whites separately until stiff peaks form. You can just add the eggs without separating them.
Place two whole organic Valencia oranges (or similar oranges) in a stockpot with enough water to cover them. The oranges will float, but they should be mostly covered. Cover and simmer for about 1 ½ to 2 hours. The oranges are ready when you can easily glide a toothpick or fork through them.
Cool the oranges for a few minutes, slice them into wedges and remove any pits or inedible parts (like the nub where the stem was).
Process the oranges until you have a smooth orange paste without orange pieces.
Preheat your oven to 325 degrees F.
Prepare a springform pan by greasing the bottom and sides. Optionally, you can line it with parchment paper if you'd like it to slide out of the pan easily. Sometimes I place parchment paper on the bottom of the pan so I can transfer it to a plate for slicing.
In a bowl or standing mixer, add the orange paste, egg yokes, honey, almond flour, baking soda, salt, and mix until well-blended. Alternatively, you can add all the ingredients to a food processor and pulse until smooth.
Whip the egg whites until fluffy and fold them into the batter.
Pour the batter into the springform pan and bake for about 1 hour, or until a toothpick inserted into the center comes out clean. Make sure to bake it thoroughly, especially in the center. It may settle a bit in when it cools.