Preheat oven to 350°. For the batter, combine coconut sugar, baking powder, cinnamon, almond milk, vanilla, egg, plain Greek yogurt, and avocado oil in a mixing bowl. Whisk until well combined.
Add the whole wheat pastry flour to the mixture and stir until just combined, don't overmix! Set aside.
Now, make the cinnamon crumble by combining coconut oil, cinnamon, coconut sugar, and whole wheat pastry flour with a fork until small crumbs form.
Fill each donut tin 3/4 full of batter, should make about 8 donuts. Sprinkle each donut with the cinnamon crumble, then bake in the preheated oven for 14-15 minutes.
Meanwhile, make the glaze by whisking together organic powdered sugar, almond milk, and vanilla until no clumps remain.
After 14-15 minutes, remove the donuts from the oven and allow to cool. Once cooled completely, then drizzle with the glaze and eat within 2 days!