1-First Step: Mix 250 ml warm milk with 50 g granulated sugar and 7 g yeast in a bowl, then let it sit for about 10 minutes until it becomes foamy. This step ensures your yeast is active and ready to help the dough rise.

2-Second Step: Add 2 large eggs, 500 g all-purpose flour, 5 ml vanilla, 8 g salt, and 100 g softened butter to the yeast mixture. Knead everything together for around 10 minutes until the dough is smooth and elastic, though it might feel sticky at first.

3-Third Step: Cover the dough and let it proof in a warm spot until it doubles in size, which takes about 1-2 hours. You can also pop it in the fridge overnight for a deeper flavor if you have time.

4-Fourth Step: In a saucepan, combine 250 g blueberries, 30 g granulated sugar, 15 ml lemon juice, and 2 g salt. Bring it to a simmer over medium heat and stir occasionally for 15 minutes until it thickens.

5-Fifth Step: Let the compote cool completely before you use it, as this helps it set up nicely for filling the donut later.

6-Sixth Step: Roll out the proofed dough to about ½-inch thickness and cut it into 3.5-inch rounds using a cutter. Place them on a floured surface and let them rest for 40-60 minutes until they’re puffy.

7-Seventh Step: Heat 1 liter of neutral vegetable oil to 340-347°F (171-175°C) in a deep pot. Fry the donut for 2 minutes per side until they’re golden brown, then remove them and toss in 200 g granulated sugar while they’re still warm.

8-Eighth Step: Once the donut are cool, make a small pocket in the side of each one. Fill it with the blueberry compote using a spoon or piping bag.

9-Final Step: Serve them right away for the best texture, as they’re freshest when warm. Remember, filled donuts last up to 2 days, but they’re best enjoyed soon. For external insight on yeast, visit yeast activation techniques to refine your skills.