In a medium bowl, whisk together Active Dry Yeast (2 tablespoon) and 3/4 of the Milk (1 cup). Allow the active dry yeast to slightly dissolve. Add 3/4 cup of Bread Flour (2 cup) and whisk together until a smooth batter is formed.
Cover the dough with plastic wrap, and let it rest in a warm place for 30 minutes.
Combine the remaining warm whole milk and Active Dry Yeast (1 tablespoon) in the bowl of a stand mixer fitted with the paddle attachment. Add the sponge, Granulated Sugar (2 tablespoon), Salt (1/2 teaspoon), Vanilla Extract (1 teaspoon), and Egg (3).
Mix until smooth. Turn off the mixer and add 1/2 cup of Bread Flour. Mix on low for about 30 seconds until the flour is just incorporated. Turn off the mixer and add the Unsalted Butter (1/4 cup). Mix once more until it is combined.
Swap out the paddle attachment for the dough hook. Add 1/4 of the remaining bread flour at a time, kneading the dough between additions, until the dough comes away from the sides of the bowl.
Cover with plastic wrap and place it in the fridge. It should rest for at least 1 hour, until it has doubled in size. It can remain refrigerated for up to 12 hours.
Place a kitchen towel, not a paper towel, on a baking sheet and sprinkle lightly with bread flour. You might need two baking sheets. Roll out the dough about 1/2 of an inch thick on a lightly floured surface.
Cut out doughnuts with a doughnut or cookie cutter. Place the doughnuts on the prepared pans, spacing them out evenly. Cover with plastic wrap and place in a warm spot.
Allow to double in size, 5 to 20 minutes, checking every 5 minutes to see if they are ready. You’ll know the doughnuts have proofed properly when you touch one lightly with your fingertip. If it springs back right away, it needs more time.
While the doughnuts are rising, preheat the Vegetable Oil (to taste) in a heavy-duty pot until it registers 360 degrees F (180 degrees C). It should have at least 2 inches of oil. Carefully drop in the doughnuts a few at a time. Do not overcrowd the pot.
Fry for 1 to 2 minutes on each side, or until light golden brown. Drain the excess oil and transfer to a cooling rack. Continue until all the doughnuts are fried.
Allow to cool and make the glaze. In a food processor, pulse the Fresh Blueberries (1 cup) until a smooth liquid forms and the berries are completely broken down. Add the Fresh Basil (1 tablespoon) and Bourbon (3 tablespoon) and pulse once more until completely smooth.
In a large bowl, combine the Powdered Confectioners Sugar (3 cup) and blueberry mixture (a spoonful at a time) until the glaze is smooth and the perfect dipping consistency. Whisk until desired consistency is reached.
Dip the doughnuts into the glaze and place on a cooling rack, allowing the glaze to set before eating. Enjoy!