• Preheat the oven to 425 degrees. Generously spray a 9X13 inch baking pan with non-stick spray.  
• In a large bowl, whisk together flour, sugars, baking powder and salt.
• In a separate medium sized bowl, whisk the eggs until frothy.  Mix in the vanilla, and buttermilk. Then mix in the melted butter. 
• Pour the wet ingredients into the dry ingredients.  Stir until just combined. Do not overmix. Pour batter into prepared baking pan. If adding toppings, follow directions below for "adding optional toppings".
• Bake for 12 minutes then check for doneness by inserting a toothpick into the center to see if it comes out clean. The pancake will slightly brown on top as it bakes, just make sure to cook until done. Make sure the pancake springs back when lightly touched.

Adding optional toppings

• If you would like to add in toppings, use a spatula or knife to mark out the four quarters of the pan.  In one quarter, sprinkle on blueberries. If desired, use a toothpick to swirl these into ¼ of the batter if you want the toppings to be baked, or you can also lightly lay them on top so they can be seen after baked. Alternately, you can use just one topping all over.