Preheat oven to 400 degrees FIn a medium saucepan combine milk, water, butter, sugar and saltHeat mixture until butter is melted and just starting to simmerAdd flour into butter mixture and stir vigorously with a wood spoon until dough comes together and create a film on the bottom of the panTransfer the dough to a mixer with paddle attachment and turn on medium speedBeat the dough on medium speed to release the steam from the dough, approximately 1 minuteSlowly add eggs one at a time until the dough comes back together and has the texture of pasteTransfer dough into a pastry bag with start tip and pipe into 4 inch long logsBake at 400 degrees F for 10 minutes and then turn oven to 375 degrees F for another 20 minutes or until golden brownShut oven off and prop open the door and leave the pâte à choux shells in for another 5 minutesRemove from the oven and allow them to cool completely before filling or store in an airtight container and freeze until ready to use.Combine milk, ½ of the sugar, and vanilla bean in a medium saucepan placed over high heatWhisk together remaining sugar, cornstarch and egg yolksOnce the milk has come to a simmer, whisking continuously slowly add â…“ of the milk mixture into the egg mixture to temper the eggsReturn the tempered egg mixture back into the saucepan and continue whisking until pastry cream becomes thick and starts to bubbleRemove the pastry cream from the heat, strain through a fine sieve, pour it into a shallow bowl and cover with plastic wrap pressed to the surface to prevent a skin formingAllow the pastry cream to cool to room temperature before refrigeratingStore in air tight container for up to 3 days if not using immediatelyBefore filling the eclairs, fold whipped cream into pastry cream to lighten up the custardMelt chocolate in a microwave safe bowlWhisk in butter into melted chocolate until smoothUsing small round pastry tip, poke 2 holes in the bottom of the pate a choux shellFill pâte à choux shell with vanilla bean pastry creamDip the top of the shell into melted dark chocolate glaze and garnish with white chocolate drizzle and gold leaf (optional)Refrigerate until ready to serve