1. Preheat the oven:  

Preheat your oven to 350°F (175°C). Grease and flour a bundt pan or loaf pan.

2. Mix dry ingredients:  

In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt. Set aside.

3. Cream butter, cream cheese, and sugar:  

In a large bowl, beat the softened butter, cream cheese, and sugar together until light and fluffy, about 3-4 minutes. This will create a rich and creamy base.

4. Add eggs:  

Beat in the eggs, one at a time, ensuring each is fully incorporated before adding the next. Add the vanilla extract as well.

5. Alternate dry ingredients and sour cream:  

Gradually add the dry ingredients to the butter mixture, alternating with the sour cream or buttermilk. Start and end with the dry ingredients. Mix gently until just combined.

6. Fold in chocolate chips:  

Carefully fold the chocolate chips (or chopped chocolate) into the batter.

7. Bake the cake:  

Pour the batter into the prepared pan and smooth the top. Bake for 55-60 minutes or until a toothpick inserted into the center comes out clean.

8. Cool and optional drizzle:  

Let the cake cool in the pan for 10-15 minutes before transferring it to a wire rack to cool completely. If you like, drizzle melted dark chocolate over the cooled cake for a decadent finish.

9. Serve and enjoy:  

Slice and serve this rich, moist, and chocolatey treat. It’s perfect for any occasion!