Preheat oven to 325 degrees Fahrenheit. Grease muffin tin or use muffin cups.
In a large bowl, beat the oil and maple syrup with an electric mixer. Add the eggs and beat well. Beat in the bananas and milk, followed by the baking soda, vanilla extract, salt and cinnamon.
Add the flour and oats to the bowl and mix with a large spoon or spatula, just until combined. Add in 3/4 cup of chocolate chips (optional).
Divide the batter evenly between the muffin cups, filling each cup about two-thirds full. Bake for 22 to 25 minutes, or until a toothpick inserted into a muffin comes out clean.
Place the muffin tin on a cooling rack to cool. Muffins will keep at room temperature for up to 2 days. They keep well in the freezer in a freezer-safe container (put paper towels underneath and on top of the muffins) for up to 3 months.
Makes 12 muffins.
Adapted from Cookies and Kate