Combine the flour, sugar, baking powder, baking soda, and salt in a medium sized mixing bowl. Measure out the oat milk in a glass measuring cup. Add the oil and whisk together. Add the milk and oil to the flour mixture and mix until fully incorporated.
If using a skillet or griddle pan, add a small amount of oil (about a teaspoon) to the pan and preheat over medium heat. If using a griddle, set the temperature to 325° F. Pour batter onto the griddle. If adding mix-ins, add them now. Cook the pancake until bubbles stop forming and edges become firm. Flip the pancake and cook for a couple of minutes longer. Remove from griddle. Repeat until the batter is gone. Serve immediately with maple syrup and other toppings if desired.