• Prepare the phyllo sheets: The box of phyllo sheets will need to be thawed overnight in the fridge. Once they are thawed, dry out the phyllo sheets on a large, clean surface for approximately two hours at room temperature. Or, you can bake the rolled out phyllo sheets in the oven for 25 minutes at 200 degrees F.
• Juice and zest six oranges. Set aside separately.

Prepare the Chocolate Orange Ganache Topping

• In a small saucepan, heat the whipping cream on low heat. Add in the icing sugar and stir together.
• Once the whipping cream is warm, add the chocolate.
• Add in 2 tablespoons of unsalted butter. Stir until it's melted in with the chocolate and cream. Keep the mixture on low heat so that the chocolate doesn't burn.
• Add one tablespoon of orange zest and 1/4 cup orange juice. Mix together.
• Let the ganache simmer on low heat for 2-3 minutes. Then remove from heat and set aside in a bowl to cool.

Prepare the Cake

• Grease a 9"x13" baking dish with unsalted butter and line with parchment paper. Set aside.
• Once the phyllo sheets are dry, use your hands to crumble them into small pieces and place the pieces in a large bowl.
• Preheat your oven to 350 degrees F on bake.
• In a separate large bowl, mix the eggs, sugar and vanilla together with an electric whisk for 5 minutes or until the mixture is pale yellow and frothy. Then add in the oil, yogurt, and remaining orange juice and orange zest. Stir together.
• Mix two tablespoons of orange juice in a small bowl with one teaspoon of baking soda. Once it foams add it to the wet ingredients.
• Slowly sift in the cocoa powder to the wet ingredients. Mix well together.
• Gradually add in the phyllo pieces a handful at a time to the wet ingredients and stir using a spoon or spatula in between handfuls. You can crumble the phyllo pieces more as you add them in. However, try not to add too much at once because they will stick together in the cake mixture.
• Once all of the phyllo is mixed well with the wet ingredients, pour the cake batter evenly into the greased baking dish. Lightly tap the cake pan on the counter a couple of times.
• Place the cake into the preheated oven and let it bake for 40-45 minutes at 350 degrees F. As the cake nears the 35-40 minute mark, you can use a toothpick to pierce the centre of the cake lightly. If it comes out with a few moist crumbs then the cake is done.
• Remove the cake from the oven and cool for 5-10 minutes in the baking dish.
• Now it's time to pour the ganache over your cake! Add a generous amount of the chocolate orange ganache while the cake is still in the baking dish. Let your cake sit for another 10 minutes with the frosting before serving. 
• Top your orange chocolate cake with fresh orange slices or zest for garnish, whipped cream, or a scoop of ice cream!