Whisk together the flour, sugar, baking powder, and salt in a medium basin.
Using a fork, mash the bananas in a large bowl until only tiny pieces remain. Mix in the oil, milk, eggs, vanilla, and milk until combined.
Mix the dry and liquid ingredients until just combined, with the exception of a few small lumps, which is acceptable. Wait five minutes.
As the batter rests, preheat over medium heat a skillet or griddle. Using quarter-cup scoops, transfer the pancake batter to the heated griddle. After 3 to 4 minutes, or until bubbles appear on the pancake's surface, turn and cook for an additional 2 to 3 minutes.
Warm and garnish with banana slices, butter, and syrup.