Preheat oven to 325 degrees. Prepare 12 cup muffin pans by lining with cupcake liners.
In a large bowl, beat the eggs, sour cream, brewed hot cocoa, oil and vanilla.
Continue beating while slowing adding the dry ingredients (flour, sugar, cocoa, salt and baking soda). Mix until well blended.
Spoon muffin batter into prepared muffin cups. Bake at 325 degrees for 25 minutes or until knife inserted into the center comes out clear. Cool for 5 minutes before removing.