Preheat the oven to 350 degrees F and spray a donut pan with non-stick spray.
Whisk the flour, brown sugar, baking powder, pumpkin pie spice and salt in a large bowl.
Pour in the melted vegan butter, pumpkin puree, oat milk and vanilla. Mix well with a large spoon until combined.
Spoon the batter into the donut pan to the top of each cavity (or use a piping bag for less mess).
Place into the oven and bake for 10-12 minutes, or until the edges are slightly browned and the donuts spring back when touched.
Make the maple glaze – In a medium bowl, whisk all glaze ingredients together until a glaze is formed. If it's too thick, add a teaspoon of oat milk at a time until you reach the desired consistency.
Dip the slightly cooled donuts in the glaze, then place on a wire rack (with parchment paper underneath to catch drippings). Enjoy right away or let the glaze harden for 15 minutes or so.
