1. In a bowl, mix oats and buttermilk; let stand at least 15 minutes or up to 30 minutes.
2. Meanwhile, in a small bowl, mix flour, sugar, baking soda, baking powder, and salt.
3. In a large bowl, beat eggs, milk, and vanilla to blend. Stir in flour and oat mixtures just until evenly moistened, then gently stir in raspberries.
4. Place a nonstick griddle or a 12-inch nonstick frying pan over medium heat (350°); when hot, coat lightly with oil and adjust heat to maintain temperature. Pour batter in 1/2-cup portions onto griddle and cook until pancakes are browned on the bottom and edges begin to look dry, about 2 minutes; turn with a wide spatula and brown other sides, 1 1/2 to 2 minutes longer. Coat pan with more oil as necessary to cook remaining pancakes.
5. Serve the pancakes as cooked, or keep them warm in a single layer on baking sheets in a 200° oven for up to 15 minutes. Stack pancakes on plates and serve with berry coulis (see notes).