Preheat oven to 350 degrees F. Spray a 10-12 inch bundt pan with non-stick cooking spray and sprinkle lightly with flour. Set aside.
Using your stand mixer or handheld, add in first seven ingredients on a low speed until everything is mixed together. Then turn the speed up to high and beat for 2 minutes. Scrape the bowl with a ladle.
Add in egg whites and return speed to high for an additional 2 minutes. Scrape bowl with a ladle one more time.
Remove 1 3/4 cups of batter into a separate bowl. Add in cocoa powder and melted baking chocolate; stir to combine.
Pour half of the white batter into the prepared bundt pan. Drop chocolate batter by the tablespoonfuls randomly over the white batter. Using a butter knife, cut through both batters to make a marble effect. Then top with remaining white batter and repeat cutting through with the butter knife.
Bake for 40-45 minutes, or until a toothpick inserted comes out clean. Let sit and cool for 10 minutes, then turn bundt pan upside down on a cooling rack to remove from pan. Let cool completely until frosting, about 1 hour.
Place heavy whipping cream in a medium glass bowl. Place in the microwave and heat for 1 minute. Making sure to stop every 30 second to stir, so milk doesn't curdle.
Once the heavy whipping cream is warmed through, add in chocolate. Stir until melted. Let stand 5-10 minutes. Ganache is ready when it mounds slightly when dropped from a spoon.
Pour ganache onto cooled marble cake and spread over top with the back of your spoon. The ganache will fall down the sides, but this is ok. Let stand for 30 minutes at room temperature.
Cut into pieces, serve and enjoy!