Pre-heat oven to 350F/180C lightly grease and flour, spray or line with parchment paper two 8 inch / 20cm cake pans.
FOR THE CAKE
Melt chocolate in a bowl over a pot of boiling water (make sure bowl does not touch the water) or in the microwave, when almost melted remove from heat and stir until smooth. Let cool.
In a large bowl beat the eggs, sugar and zest until light and fluffy (approximately 4-5 minutes). Add both the yogurt amounts and combine then slowly drizzle in the oil and combine until smooth.
In a medium bowl whisk together the flour, baking powder, baking soda and salt, then add to yogurt mixture and combine, add the melted cooled chocolate and combine. Divide evenly into the prepared cake pans and bake for approximately 30-45 minutes (or until toothpick comes out dry or a few crumbs attached). Let cool completely before frosting.
FOR THE FROSTING
In a large bowl whip the cream until soft peaks appear, then add the cream cheese, sugar and zest continue to beat until thick.
Decorate the cake with orange slices or even chopped chocolate or chocolate curls, or if you prefer leave it plain and add a dusting of powdered sugar. Enjoy!
Notes
Make your own cake flour: Measure out one cup of all purpose flour. Remove two tablespoons of flour and replace with two tablespoons of cornstarch. Sift together.I use a dark chocolate chocolate bar with 52% cocoa. If you want an even more richer intense flavor then 70% cocoa content is perfect.Store at room temperature in an airtight container for up to 2 days. Store in the refrigerator up to 5 days.