An extremely rich dark chocolate cake that is not only flavored with cocoa powder, but also contains chunks of 100% dark chocolate and semisweet chocolate chips. Frost it with dark chocolate ganache for a luxurious treat.
Preheat oven to 350F. Line baking pans with parchment paper.
Cream together the butter and sugar in a large bowl. Add cocoa powder, vanilla extract, and eggs one at a time.
Add in chocolate chips and broken up pieces of the 100% chocolate bar. Mix well to incorporate.
Carefully add and mix in the flour.
Pour into lined pans and bake for 30-40 minutes.
Remove from pans and let cool. When cooled to room temperature (or in a fridge), top with dark chocolate ganache and serve.