For the white chocolate custard sauce: Combine the half-and-half and vanilla bean and seeds in a small saucepan over medium heat and bring to a simmer. Remove from the heat and let cool slightly.
Whisk together the egg yolks and granulated sugar in a medium bowl until pale yellow. Slowly whisk in some of the warm half-and-half mixture until smooth. Pour the mixture back into the saucepan and cook over medium heat, stirring with a wooden spoon, until it thickens slightly and coats the back of the spoon. Do not boil. Remove from the heat, add the white chocolate and whisk until smooth. Strain into a bowl, cover, and chill until cold.
For the chocolate-espresso whipped cream: Combine the cream, cocoa nibs and espresso beans in a small saucepan and bring to simmer. Immediately remove from the heat and refrigerate until cold. Strain the cream into a chilled bowl, add the cocoa powder, confectioners' sugar and vanilla and whip to soft peaks.
For the dark chocolate waffles: Whisk together the flour, cocoa powder, baking powder, baking soda and salt in a large bowl. Whisk together the egg yolks and brown sugar until smooth. Add the buttermilk, oil and vanilla and whisk until combined. Add the wet mixture to the dry mixture and mix until just combined. Fold in the butter and chocolate.
Whip the egg whites in a medium bowl until soft peaks form. Fold the whites into the batter.
Heat a waffle iron according to the manufacturer's instructions. Brush the grates with butter and ladle 1/4 cup of batter in each grate, close, and cook until crisp and browned and steam stops coming from the waffle iron, 4 to 5 minutes. Repeat with the remaining batter. Serve with the custard sauce, whipped cream, some strawberries and a dusting of confectioners' sugar.