Preheat the oven to 400℉. Grease two donut pans.

In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, apple pie spice, and salt until combined.

In another mixing bowl, whisk together the applesauce, olive oil, milk, and vanilla until smooth and combined.

Fold the applesauce mixture into the dry ingredients until just mixed and no streaks of flour remain.

Transfer the batter to a piping bag, snip off the corner, and pipe the batter into the donut pans, filling each mold almost to the top.

Bake for 10-12 minutes until golden brown and a toothpick inserted into the center comes out clean.

Remove from the oven and let cool in the pans for 10 minutes before transferring to a baking rack to cool.

Once cool enough to handle, dip each donut in melted butter followed by the sugar topping until well-coated.