Warm the milk to about 105F (40C) degrees. Add the milk to a mixing bowl.
Add the sugar and stir to dissolve. Add the yeast and stir to combine. Let the yeast rest for 5 minutes.
Add the beaten eggs and melted butter to the bowl and stir to combine.
While the mixer is running slowly, add the flour and salt and mix until the dough comes together.
Turn off the bowl and let the dough sit in the bowl of the mixer for 10 minutes.
After the rest period, turn the dough out into a lightly oiled bowl, cover the bowl with plastic wrap and refrigerate the dough for at least 2 hours.
To form the Donuts
Remove the dough from the fridge and roll it out on a lightly floured surface until it is 1/2 to 1/3 of an inch (about 1 cm) thick. Using a ring cutter, cut the donuts.
Place the cut donuts and holes on a lightly greased baking sheet.
Cover the donuts and let them rise until doubled in size, about one hour.
To fry the Donuts
Heat the oil until it reaches 350 to 375 degrees (180C).
Add the donuts to the hot oil and fry until golden brown, about 1 1/2 minutes per side.
To make the Prune Jam
Bring prunes and water to a simmer, then cover and cook until prunes are meltingly tender, about 15 minutes, cook until the liquid in the pan is syrupy. * (Depending on the moisture content of your prunes, you may need to add more water to keep prunes from drying out)
Transfer mixture to a food processor and add kosher salt, then pulse until it develops into a thick paste.
Add sugar in 2tablespoon increments to desired sweetness.
Use immediately, or transfer to a clean jar, seal, and chill in the refrigerator for at least 4 hours.
To make the Vanilla Glaze
Melt butter in a medium bowl.
Add vanilla and stir to combine.
Add powdered sugar and stir to form a thick paste. Thin out the paste with milk, one tablespoon at a time.
Glaze donuts!
To make the Honey Walnut Crumble
Melt butter and set aside.
Mix dry ingredients, set aside.
In a stand mixer, add butter, honey, and dry ingredients until a crumble forms
Bake at 350ºF (180C) for 15 min until golden.
Assembly
Once the donuts are slightly cooled, pipe prune jelly inside then glace the top. Sprinkle the walnut honey crumble on top and decorate with an edible flower if desired. Enjoy your Jelly Donut!