Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners.
In a large bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, and salt.
In another bowl, mix the vegetable oil, eggs, vanilla extract, and milk until well combined.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Gently fold in the chocolate chips.
Divide the batter evenly among the muffin cups, filling each about 2/3 full.
Bake in the preheated oven for 18-20 minutes or until a toothpick inserted comes out clean.
Allow the muffins to cool in the pan for 5 minutes, then transfer to a wire rack.
Enjoy warm or at room temperature.
Store any leftovers in an airtight container at room temperature for up to 3 days.