Jam-Filled Challah Doughnuts

• 1 1/2 teaspoons active dry yeast
• 1 tablespoon plus 1/4 cup sugar
• 5 large egg yolks
• 1 teaspoon kosher salt
• 2 1/3 cups all-purpose flour, plus more
• 6 tablespoons unsalted butter, room temperature, cut into pieces
• Vegetable oil (for bowl)
• Vegetable oil (about 8 cups; for frying)
• 1 cup sugar
• 1 1/2 cups any flavor seedless jam
• A 2-inch-diameter biscuit or cookie cutter, deep-fry thermometer, pastry bag, and 1/4-inch-diameter pastry tip

1. Mix yeast, 1 Tbsp. sugar, and 1/2 cup warm water in the bowl of a stand mixer fitted with paddle attachment to combine; let sit until mixture is foamy, 8-10 minutes.
2. Add egg yolks, salt, and remaining 1/4 cup sugar and beat on medium-low speed to combine, about 1 minute. Increase speed to medium and gradually add 2 1/3 cups flour; mix until combined and thick, about 3 minutes. Remove paddle, scrape down mixture back into bottom of bowl, and swap in dough hook.
3. With mixer on low speed, add butter a piece at a time, mixing until incorporated after each addition. Once all the butter has been added, mix until dough is smooth, shiny, and elastic, about 5 minutes.
4. Turn dough out onto a lightly floured surface and knead, adding more flour by the tablespoonful, until no longer sticky, about 3 minutes. Place dough in a lightly oiled large bowl and turn to coat. Cover loosely with plastic wrap and let rise in a warm, draft-free spot until doubled in size, about 1 hour.
5. Punch down dough and roll or pat out on a lightly floured surface to 1/2" thick. Punch out rounds of dough with cutter and place on a parchment-lined baking sheet, spacing 1" apart. Reroll scraps once and cut out more rounds. Cover doughnuts loosely with plastic wrap and let rise until not quite doubled in size, 30-40 minutes.
6. Fit a large heavy saucepan with thermometer; pour in oil to come 3" up sides and heat over medium-high until thermometer registers 350u0b0F. Working in batches and adjusting heat to maintain oil temperature, fry doughnuts, turning once, until golden brown, about 2 minutes. Transfer to a paper towel-lined baking sheet; let cool slightly.
7. Place sugar in a medium bowl, and working in batches, toss doughnuts to coat. Transfer back to baking sheet.
8. Stir jam to loosen and spoon into pastry bag fitted with tip (or use a squeeze bottle). Working one at a time, poke a small hole into side of doughnuts (a chopstick works great) and gently pipe in a generous amount of jam.

active dry yeast, sugar, egg yolks, kosher salt, flour, unsalted butter, vegetable oil, vegetable oil, sugar, cookie cutter

Taken from www.epicurious.com/recipes/food/views/jam-filled-challah-doughnuts (may not work)