Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, sugar, salt and baking soda, stirring with a whisk; add the vanilla bean. Store in an airtight container for at least 2 days. Remove bean, and reserve for another use.
Combine buttermilk and eggs in a large bowl, stirring with a whisk.
Add flour mixture to buttermilk mixture, stirring with a whisk until well combined.
Heat a nonstick griddle or skillet coated with cooking spray over med heat.
Spoon a scant 1/4 cup batter per pancake onto griddle. Turn pancakes when tops are covered with bubbles and edges look cooked. About 3 minutes.