Who says potatoes don’t belong in sweets? In these best-selling doughnuts, they’re the stealth ingredient that ensures a moist crumb and a perfect carrier for bold chocolate flavor. Feature them at breakfast or brunch, or pair them with a rich crème anglaise as a signature dessert offering.
3 sticks unsalted butter
1 Vanilla Bean
8 cups medium diced, peeled russet potatoes
2-1/2 cups granulated sugar
About 4 cups whole milk
2 cups Dark chocolate chips
2 cups sweet chocolate chips
2 Tablespoons unsweetened cocoa powder
4 large eggs
4 cups All-purpose flour
4 cups pastry flour
1/4 cup baking powder
1 tablespoon baking soda
2 cups sour cream
1/2 cup buttermilk
Cinnamon sugar as needed
4-1/4 cups whole Milk
4-1/4 cups heavy cream
1 Vanilla Bean
20 large egg yolks
2 cups granulated Sugar
For the doughnuts: Put 1 tablespoon of the butter in a large saucepan over medium heat. Scrape in the seeds from the vanilla bean. Once the butter melts and the vanilla is fragrant, add the potatoes, 1 cup of the sugar, and then enough milk to cover. Simmer until tender.
Meanwhile, combine the chocolates, cocoa powder and remaining 2 tablespoons of the butter in a bowl that will fit over the saucepan with the potato mixture. (You will be using the heat from the potatoes to melt the chocolates.) Set the bowl on top, stirring to combine as the chocolates and the butter melt. Carefully remove from the heat.
Strain the potatoes, spread on a baking sheet, and let cool as some of the liquid evaporates, about 10 minutes.
While the potatoes are cooling, in the bowl of a stand mixer fitted with the whisk attachment, mix the eggs and the remaining 1-1/2 cups of sugar together, starting on medium speed and increasing to medium-high, stopping once or twice to scrape down the sides, until the mixture has thickened. When the whisk is lifted the mixture should form a slowly dissolving ribbon.
In a medium bowl, combine the all-purpose and pastry flours, baking powder, and baking soda.
In a large bowl, with a spatula, combine the chocolate mixture with the sour cream, the buttermilk and then the egg-sugar mixture. The mixture should resemble a shiny chocolate pudding.
Pour a few inches of oil into a stockpot and heat the oil to 350˚F/177˚C. Alternatively, preheat a deep-fryer to 350˚F/177˚C. Set a cooling rack over a baking sheet. Put the cinnamon sugar in a wide bowl to toss the doughnuts into.
Set a food mill over the bowl with the chocolate mixture. Pass the potatoes through the food mill into the bowl and mix in. Stir in the combined dry ingredients, mixing with the spatula until thickened. Then switch to gloved hands and continue to mix until the dough no longer sticks to your gloves and has a nice sheen. The dough should have the appearance of an aerated chocolate. Transfer to a baking sheet.
Pinch off 1-ounce pieces of dough (about the size of ping pong balls) and roll into balls.
Working in batches, fry the doughnuts for about 6 minutes, turning as needed to brown evenly and cook through. Transfer to the cooling rack, cool for 30 seconds and then toss into the cinnamon sugar.
Serve warm with the anglaise on the side.
For the anglaise: Prepare an ice bath.
Combine the milk and cream in a large saucepan and scrape in the seeds from the vanilla bean. Bring to a simmer (195– 205˚F/90.5–96˚C) over medium heat.
Meanwhile, in the bowl of a stand mixer fitted with the whisk attachment, whip the egg yolks and 1 cup of the sugar until light in color. When the whisk is lifted there will be lines where the whisk had been.
Slowly whisk the cream mixture into the yolk mixture until all has been incorporated.
Return the mixture to the saucepan over medium heat, stirring constantly and scraping the bottom and sides often with a spoon. Cook until thick enough to coat the back of the spoon and steam begins to rise from the top (175–180˚F/79.4–82.2˚C).
Immediately strain the mixture and let cool over the ice bath. The anglaise can be refrigerated for up to 2 days.