Classic jam donuts

Ingredients:

• 3/4 cup whole milk
• 1 packet (7 g) of active dry yeast
• 0.5 cup + 3 tablespoons sugar
• 30.5 cups premium flour + extra for work
• 1 teaspoon coarse salt
• 3 large eggs, room temperature
• 1 tsp vanilla extract
• 4 tablespoons unsalted butter, cut into 4 pieces, at room temperature
• Cooking spray
• Vegetable oil, for frying
• 1 and 3/4 tbsp. confiture or jam

Preparation:

1. Pour the milk into a small bowl and microwave to 40°C-43°C. Stir in the yeast and 3 tablespoons of sugar; let stand until foamy, 3-5 minutes. In the bowl of a stand mixer fitted with a dough hook, combine the flour and salt.
2. Add the yeast mixture, eggs, and vanilla to the flour. Mix on medium speed until the dough comes together, 1 to 2 minutes. Beat in the butter, 1 piece at a time. Continue mixing, scraping the sides of the bowl occasionally with a rubber spatula, until the dough is smooth and elastic, about 6 minutes (it will be slightly sticky). Lightly spray a large bowl with cooking spray. Transfer the dough to the bowl, cover tightly with plastic wrap, and let rise in a warm place until doubled in size, about 1 hour.
3. Line 2 baking sheets with parchment paper and dust with flour.
4. Turn the dough out onto a well-floured surface and gently flatten it into a 1 cm thick layer. Using a 3-inch round cutter, cut out 12-14 circles of dough as close together as possible. Place the circles on the prepared baking sheets, spacing them 1.5 inches apart. Lightly spray the surface of the dough with cooking spray. Cover with plastic wrap and let rise for 30-45 minutes.
5. In a heavy-bottomed saucepan, heat 2 inches of vegetable oil to 300°F (150°C) on a deep-fry thermometer. Cut parchment paper around each dough circle to allow for individual lifting. Fry the doughnuts in batches of 3-4, dropping them from the parchment sheets into the hot oil. Fry, turning occasionally, until golden brown, 2.5 minutes. Transfer with a slotted spoon to a paper towel-lined baking sheet to drain excess oil. Reheat the oil to 300°F (150°C) after each batch of doughnuts.
6. Place the remaining 1/2 cup sugar in a medium bowl. While the donuts are still hot, roll them in the sugar to coat completely, then transfer them to a wire rack to cool completely.
7. Using a wooden skewer or chopstick, poke a hole in the side of each donut, swirling the skewer to create a pocket inside. Fill a pastry bag fitted with a small round tip with jam and pipe about 2 tablespoons of filling into each donut.
   
   

   Blueberry-Lemon-Poppy

   
   Don't coat the donuts in sugar (step 5). Fill the donuts with blueberry jam. Top with lemon glaze (whisk together 1 cup powdered sugar, the zest of 1 lemon, 2 tablespoons lemon juice, and a pinch of salt). Sprinkle with poppy seeds.
   
   

   Apple-Cinnamon

   
   In step 5, roll the donuts in cinnamon sugar (mix 3/4 cup sugar with 1 tablespoon ground cinnamon). Fill the donuts with apple butter.
   
   

   Lemon-Raspberry

   
   In step 5, roll the donuts in raspberry sugar (in a food processor or spice grinder, puree 1/2 cup freeze-dried raspberries until finely ground; mix with 1/3 cup sugar). Fill the donuts with lemon curd (beat 1/2 cup heavy cream until stiff peaks form, then fold in 1 cup lemon curd).
   
   

   Strawberry-Chocolate

   
   Don't coat the donuts in sugar (step 5). Fill the donuts with strawberry jam. Top with chocolate glaze (melt 170g finely chopped semisweet chocolate with 1/3 cup heavy cream and a pinch of salt in the microwave, then stir until smooth).