Preheat the oven to 350°F (175°C). Grease the baking pan.
In a large bowl, combine flour, cocoa powder, baking powder, baking soda, and salt.
In another bowl, beat sugar, eggs, sour cream, oil, and vanilla until smooth.
Gradually add dry ingredients, mixing until just combined.
Fold in chocolate chips and raspberries gently.
Pour the batter into the pan and spread evenly.
Bake for 45 minutes or until a toothpick comes out clean.
Let it cool before slicing.