Preheat oven to 350°F and lightly grease a donut pan. In a large mixing bowl, whisk together flour, sugar, and baking powder. If using, mix in freeze-dried strawberry powder. In a separate mixing bowl, whisk together non-dairy milk, melted vegan butter, applesauce, vanilla extract, and strawberry puree until smooth. Pour wet ingredients into dry ingredients and mix until just combined. Do not overmix.
Spoon or pipe batter into donut pan, filling each about 3/4 full.
Bake for 10–13 minutes, or until donuts are set and lightly springy.
Let cool completely before removing from pan.
Whisk together powdered sugar, strawberry puree, and vanilla extract until smooth and thick enough to coat. Adjust consistency if needed.
Dip cooled donuts into glaze and let set before serving.