Preheat oven to 350 degrees. Line two cupcake pans with liners and set aside.

In a medium bowl, mix flour baking soda and salt and set aside.

In another bowl mix beat butter, sugar and vanilla bean seeds until fluffy, about three minutes.

Add eggs one at a time beating until smooth, scraping down the sides of the bowl between each egg.

Mix in vanilla extract and buttermilk.

Add one third of flour mixture, alternating with buttermilk mixture until combined, and ending with the flour mixture.

Fill cupcake cups two thirds the way full and bake for 18-20 minutes or until a the cupcake springs back.

Remove cupcakes and cool on rack.

Beat butter, cocoa powder, and powdered sugar on medium speed until smooth.

Add vanilla and salt and blend until smooth.

Add sour cream one tablespoon at a time until desired consistency.

Add melted chocolate in a slow stream while beating frosting on medium speed. (If you don't beat while adding, chocolate may seize up.)

Beat on high until fluffy.

Pipe frosting onto each cupcake, using your desired tip.

If desired, sprinkle additional chocolate shavings onto cupcakes for garnishment.