Make the doughnut dough:
In the bowl of a stand mixer fitted with the dough hook, combine the water, vanilla, yeast, eggs, and sugar. Gradually add in the flour then salt, mixing until absorbed. Add the butter and cream and beat on medium speed for 6 to 8 minutes, or until a smooth sticky dough forms. Remove the dough to a lightly greased bowl, cover, and let rise until doubled in size, about 1 to 1 1/2 hours. At this point the dough can also be refrigerated and allowed to rise overnight.
Finish the doughnuts:
On a lightly floured work surface, roll the dough out to about 1/2-inch thickness. Using a round cookie cutter, cut out 6 rounds from the dough. OR, tear off pieces of dough weighing 100 grams each and shape into balls. Place on a large parchment-lined baking sheet spacing far apart. Cover and let rise until puffy, about 30 minutes.
Meanwhile, preheat the oven to 350°F. Bake the doughnuts for about 12 to 15 minutes, or until golden brown and puffed.
For the filling:
In a medium bowl using an electric mixer, beat the cream cheese, peanut butter, heavy cream, sugar, and vanilla until very well combined.
Remove the cream cheese mixture to a piping bag fitted with a long filling tip. Insert the tip into the side of a doughnut and squeeze the filling inside to fill. Repeat for the remaining doughnuts.
Make the glaze:
In a medium saucepan over medium heat, combine the butter, milk, corn syrup, and vanilla and heat until the butter melts. Decrease the heat to low and add the chocolate, whisking until melted. Turn off the heat and add the powdered sugar, whisking until smooth.
Immediately dip the doughnuts into the glaze. Place glazed doughnuts on a wire rack above a lined sheet pan to catch any excess glaze. If the glaze begins to set return the saucepan to low heat and stir until liquid again. Let the glaze set on the doughnuts for 30 minutes before serving.
Doughnuts are best served the day they’re made.