Preheat the oven to 180 degrees! Carefully grease the muffin tin cavities or line them with paper baking cups!
In a medium bowl, carefully mix the dry ingredients, meaning flour, baking powder, baking soda, cocoa powder, and chocolate chips!
In another large bowl, crack the egg and lightly whisk it! Then add sugar, oil, vanilla sugar, and buttermilk and mix well! Add the dry ingredients and carefully fold them in until just moist!
Fill the muffin tin cavities 3/4 full with the batter! Bake at 180 degrees on the middle rack for 20 to 25 minutes!