Line a 12 cavity muffin tin with muffin liners (or spray with non stick spray). Preheat the oven to 360°F.
Combine the flour, cocoa powder, baking powder, baking soda and salt in a large bowl.
In a separate smaller bowl, whisk together the oil, mashed bananas, sugar, egg, milk and vanilla extract. Pour these wet ingredients into the bowl with the flour mix and fold together with a spatula until just combined. A few lumps are OKI!
Fold in the chocolate chips. Evenly distribute the batter between the prepared muffin cups. (There are about 3 tablespoons of batter per muffin.)
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted in the middle of a muffin comes out clean. Cool in the pan for 5 minutes, then remove onto a cooling rack to cool completely.
Bananas: Please use overripe bananas for these muffins! A lot of the flavor and sweetness comes from this very soft and sweet fruit, so the muffins will not taste the same if your bananas aren't overripe.
Flour: All-purpose, whole wheat or white whole wheat flour all work here. If using whole wheat or white whole wheat, add 1-2 extra tablespoons of milk.
Oil: I used canola oil, feel free to use any neutral vegetable oil suitable for cooking and baking you have. Melted coconut oil also works great, and so does melted butter!
Milk: Any milk you like can work here. Cow's milk or plant-based doesn't matter. This is a great recipe to make dairy-free with something like almond milk and dairy-free dark chocolate chunks.
Chocolate: I love using dark chocolate chunks (I just chop up a bar), but feel free to use milk or semi-sweet chocolate chips instead!
Make sure you do not overmix the batter, otherwise the muffins will come out dense and gummy.
Leave the muffins to cool in the pan for the first 5 minutes after baking, so they can cool down a bit and firm up before you remove them to a cooling rack.
Counter: The muffins keep well for a few of days if you store them in an airtight container. They will get dry over time, but thanks to initially being very moist they are still very delicious even after three or four days.Freezer: You can easily freeze them for up to three months, too. I would advice to freeze them in freezer containers, making sure they don’t touch so you can just grab however many you need to defrost at a time.