Warm up the milk in a saucepan over medium heat then add the vegan butter to melt completely. While the milk mixture cools to lukewarm, sprinkle the yeast over the warm water, whisk and let it dissolve for 5 minutes. The top has a layer of foam when it is ready.
In a stand mixer, incorporate the milk mixture with the yeast mixture. Add the eggs, sugar and half of the flour. Using the paddle attachment, combine the mixture on low-speed until the flour is incorporated and then turn the speed to medium and beat until well combined. Add the remaining flour and beat well.
Change to the dough hook attachment on the stand mixer and beat on medium speed until the dough pulls away from the bowl and is very smooth, around 3 to 4 minutes. You want the dough to be a bit sticky since it will make for a lighter doughnut.
Transfer the dough to a well-oiled bowl, cover and let it rise for 1 hour. Once it doubles in size, punch down the dough, cover, and let it rise for 1 more hour. Then place the dough in the refrigerator and let it sit overnight to develop the flavor. If you are pressed for time, you can skip the fridge and just get started on baking the doughnuts.
In the meantime, make the simple Apricot-Plum Filling. Add the chopped apricots, plum preserve, maple syrup, cinnamon and clove in a small saucepan and simmer for 15-20 minutes, or until the apricots are soft and combine with the other ingredients. Let the mixture cool before moving on to the next step
When the dough is ready and the filling is cool, roll to ½-inch thick on a lightly floured surface. Cut out rounds using a 2½-inch wide drinking glass or cookie cutter.
Place half of the dough rounds on a cookie sheet lined with parchment paper and drop teaspoons of cooled apricot-plum filling in the center.
Brush the edges with milk (you can also use water) and place another round of dough over and press to seal tightly. You don’t want that delicious filling escaping! Covered the uncooked doughnuts and let rise for 30 minutes
Bake the doughnuts at 375 degrees for 12-15 minutes, until the bottoms just turn brown. While the doughnuts are still warm, dip them in some melted vegan butter and coat in the cinnamon sugar mixture.