1½ cups all purpose flour
¾ cup brown sugar firmly packed
½ cup cocoa powder
2 teaspoons baking powder
1 teaspoon baking soda
½ teaspoon salt
8 Tablespoons salted butter melted and cooled
⅔ cup milk
2 eggs
¾ cup dark or semisweet chocolate chips plus more for topping

Preheat the oven to 425°F. Line a muffin pan with 12 paper liners.For bakery-style muffins, line every other hole in a muffin pan with paper liners. You may want to use two pans or bake in two batches.
In a large bowl, add the flour, brown sugar, cocoa powder, baking powder, baking soda, and salt. Break up any large clumps with your fork or whisk and mix together. Set aside.
1½ cups all purpose flour
¾ cup brown sugar
½ cup cocoa powder
2 teaspoons baking powder
1 teaspoon baking soda
½ teaspoon salt
Whisk together the milk and eggs in a measuring cup until combined.
⅔ cup milk
2 eggs
Add the milk mixture and melted butter to the dry ingredients, and fold together with a spatula until only a few streaks of flour remain. Add in the chocolate chips, and fold until just combined. The batter will be thick.
8 Tablespoons salted butter
¾ cup dark or semisweet chocolate chips
If you haven't already, preheat the oven to 425°F
For the tallest muffins, line every other hole in a muffin pan with paper liners. You may want to use two pans or bake in two batches.
For regular muffins, line a muffin pan with 12 paper liners.
Scoop the muffin batter into the paper liners, about ⅔ of the way full, then top with more chocolate chips if desired.
Bake for 5 minutes at 425°F, then reduce the temperature to 350°F and bake for an additional 13-16 minutes, until a toothpick inserted in the center comes out clean. Let cool, then enjoy!