▢3 cups all-purpose flour ▢1 cup Dutch process cocoa powder or unsweetened cocoa powder ▢¾ cup sugar ▢1 tablespoon baking soda ▢½ teaspoon salt ▢2 cups milk ▢½ cup vegetable oil ▢3 large eggs ▢2 teaspoons vanilla extract ▢¾ cup semisweet chocolate chips plus more for topping ▢½ cup milk chocolate chips plus more for topping
Preheat the oven to 350°F. Prepare a 24-cup muffin tin or two 12-cup tins with liners or cooking spray. Set aside.
In a large bowl, combine flour, cocoa powder, sugar, baking soda, and salt.
In a separate bowl, combine milk, oil, eggs, and vanilla. Whisk until incorporated and egg yolks are broken. Fold in chocolate chips.
Fold the wet mixture into the dry ingredients. Do not overmix, but make sure you do not have any dry spots. Spoon batter into the prepared tins to fill about three-quarters of the way full. Sprinkle on additional chocolate chips.
Bake for 20–22 minutes, or until an inserted toothpick comes out clean. Cool in tins for about 10 minutes before moving to a wire rack to cool completely.