Preheat your oven to 180°C (350°F). Grease and line a 20 cm (8-inch) round cake pan. This ensures the cake releases easily after baking.

In a large bowl, cream together the *sugar* and *butter* until light and fluffy. Add the *eggs* one at a time, mixing well after each addition.

In a separate bowl, sift together the *flour*, *baking powder*, *baking soda*, and *salt*. Gradually add the dry ingredients to the wet mixture, alternating with the *orange juice* and *Greek yogurt*, beginning and ending with the dry ingredients.

Stir in the *orange zest* and *cocoa powder* until fully combined. Finally, fold in the *melted dark chocolate*.

Pour the batter into the prepared pan and smooth the top. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

While the cake is cooling, prepare the frosting. In a large bowl, beat the *cream cheese* and *butter* together until smooth and creamy.

Gradually add the *powdered sugar*, one cup at a time, beating well after each addition. Once all the sugar is incorporated, add the *vanilla extract* and continue beating until light and fluffy.

Stir in the *melted dark chocolate* and *orange zest* until fully combined. The frosting should be creamy and spreadable.

Once the cake has fully cooled, place it on a serving plate. Spread a generous layer of frosting on top. If desired, garnish with extra *orange zest* or *chocolate shavings*.

Cut into slices and serve. Enjoy your delicious homemade *Orange Chocolate Cake*! This cake is perfect for holidays or any special occasion.