Preheat oven to 425 degrees F. Lightly coat a 12 by 17 inch rimmed sheet pan with the vegetable oil and line the pan with parchment paper - making sure to press the paper into the bottom so that it sticks.
Whisk together the buttermilk, eggs, vanilla and melted butter.
In a separate bowl whisk together the flour, sugar, baking powder, baking soda and salt.
Pour the buttermilk mixture into the bowl with the flour mixture. Mix the pancake batter until smooth with a wooden spoon or spatula. Spread the pancake batter evenly into the bottom of the prepared sheet pan.
Evenly top the batter with raspberries (or blueberries, bananas, chocolate chips - or whatever you would like in your pancakes).
Bake for 11 - 13 minutes, or until pancake is puffed and springs back when lightly touched.
Allow to cool in the pan for a few minutes before slicing. Serve right away or allow to cool completely and store in the freezer with parchment paper separating the slices of pancake.