Preheat oven to 400F. Line a jumbo muffin pan with 6 large muffin liners. Set aside. In a large bowl, whisk together the flour, cocoa powder, white sugar, baking powder and salt until completely combined.
Make a well in the center of the dry ingredients and add the milk, greek yogurt, eggs, vanilla extract and vegetable oil. Stir well until wet ingredients are well combined into the dry ingredients and no dry steaks remain in the batter.
Add the chocolate chips and gently fold in. Divide the muffin batter evenly amongst the 6 prepared liners.
Bake for 5 minutes, then reduce heat from 400 F to 350F and continue to bake for 25-30 minutes until an inserted toothpick comes out mostly clean with crumbs attached.