Preheat oven to 350 °F and place 6 oven proof glasses (or ramekins) in a baking dish with a 2-inch lip.
Scrape seeds from vanilla bean into a small saucepot with ½ cup whipping cream and white chocolate. Stir over low heat until melted and remove from heat. In a bowl, whisk remaining 1 ¼ cups whipping cream, sugar, egg yolks, whole eggs and sour cream. Whisk in chocolate mixture. Divide custard in half. Whisk coffee granules and coffee liqueur into one half of custard and spoon or ladle 2 ounces of that coffee custard into each glass ramekin. Pour boiling water (or very hot tap water) around ramekins up to the height of the custards and bake for 25 minutes, until set. Remove from oven and let rest 5 minutes.
Ladle white custard over the cooked coffee custards gently by pouring over the back of a spoon into glass (just like a bartender layers drinks). Top up baking pan with hot water if necessary and bake for 30 minutes, until custards just shake a little when tapped. Remove ramekins from water bath, let cool to room temperature then chill completely before serving, at least 4 hours.
Serve with Mocha Pinwheels.
Beat butter and cream cheese together. Add sugar and cream until smooth. Stir in egg and vanilla. Stir in flour and baking powder and blend just until dough comes together. Shape dough into a disk and chill for an hour.
On a lightly floured surface (or between 2 sheets of parchment paper) roll out pastry to ¼ -inch thick in a rectangle. Brush pastry with melted butter and sprinkle evenly with instant mocha powder. From a long end, roll up pastry into a pinwheel, wrap and chill for an hour.
Preheat oven to 350 °F. Slice pinwheels into ¼ -inch rounds and place an inch apart on a parchment-lined baking sheet. Bake for 8 to 10 minutes, until pinwheels brown lightly. Remove from pan to cool completely.