Preheat oven to 350 deg.place baking rack in center of oven,line dozen muffin cups with cupcake papers. Into medium bowl,sift together the flour,cocoa powder,baking soda and salt.Gently wisk the dry ingredients together until blended;set aside. In a heavy-duty electric mixer using the paddle attachment,beat the butter with the sugar at medium speed until thoroughly blended,about 2 minutes. Beat in the egg and vanilla;scrape down the sides of the bowl with a spatula and beat for 1 minute,until well blended.Beat in the chocolate.At low speed,beat in the buttermilk one-third at a time,alternating it with the dry ingredients. Mix just until blended,scraping down the side of the bowl as necessary. Divide the batter among the prepared muffin cups and bake the cupcakes for 25 -30 minutes,until they spring back back when lightly touched. Cool cupcakes in the pan for 5 minutes,then remove to a wire rack and cool completely. Making the white chocoalate filling: Place the white cho colate in a stainless steel bowl,In a saucepan,bring the heavy cream to a gentle boil. Remove the pan from the heat and pour the hot cream over the whitechocolate.Let the mixture stand for 30 minutes to melt the chocolate:whisk until completely smooth.Cover the bowl and refrigerate the filling for at least 4 hours,until Well chilled. Using a hand-held electric mixer,whip the chilled white chocolate mixture until it reaches the consistency of sour cream. With a small knife,cut a cone shaped peice, 2 cm in diameter,from the center of each cupcake.Remove the the cone shaped piece of cupcake,and cut off the bottom of each cone,leaving a round cap for each cupcake. Discard or eat(VBG) the cone bottoms and retain the caps. Fill pastry bag fitted with a medium plain tip with the white chocolate filling.Pipe the filling into the hole in each cupcake. Cover the filling with the reserved caps. Place the filled cupcakes in a airtight container and place in the refrigerator while making the glaze. Dark Chocolate Glaze Place the chocolate in athe bowl of a food processor fitted with the metal chopping blades.Process the chocolate until finely ground,20 to-30 seconds. In a small saucepan,bring the cream and the corn syrup to a gentle boil.With the motor runnign,poor the hot cream through the feed tube onto the chocolatee. Process until smooth,about 10 seconds. Pour the glaze into a medium bowl. Cover the bowl with plastic wrap and refrigerate for 30 minutes,until slightly thickened. Remove the cupcakes from the refrigerator.Dip the top of each cupcake into the glaze and allow the excess glaze to drip off. Place the cupcakes in the refrigerator for 10 minutes,to set the glaze. Remove the cupcakes from the refrigeratorand re-dip the top of each cupcake in the glaze. Set the glazed cupcakes aside at room temperature. Melt the white chocolate according to the directions: In microwave ..Place chopped chocolate in microwave-safe ccontainer and microwave at Medium for 1.5 to 4 minutes,until chocolate turns shiny. Remove from microwave and stir until completely melted.stir about 1.5 minutes. Fill a small pastry bag or parchment cone fitted with a small plain tip withthe white chocolate.Drizzle athe chocolate in a zigzag pattern over the top of the glazed cupcakes. Chill before serving... Sorry, I just shredded the white chocolate for garnish..... These are very good,very rich but wonderful when you want to impress the crowd... Louise Recipe By : From the Chocolatier