Preheat your oven to 180°C (356°F). Grease a donut pan.
In a small bowl, mix the plant-based milk and apple cider vinegar. Let it sit for 5 minutes.
In a large bowl, mix the flour, sugar, baking powder, salt, and ground cardamom.
In another bowl, mix the melted coconut oil, chopped pistachios, and acidified plant-based milk. If the coconut oil is in solid form, melt it using a double boiler or microwave until it is liquid before adding it to the wet ingredients. Be careful not to overheat it, as it can become too hot and lose some of its beneficial properties.
Add the wet ingredients to the dry ingredients and mix until you get a homogeneous batter.
Pour the batter into the donut molds, filling them 3/4 full, using a piping bag.
Bake for 12-15 minutes or until a toothpick comes out clean.
While the donuts are cooling, prepare the glaze. Mix the powdered sugar, plant-based milk, and pistachio paste until you achieve a smooth consistency.
Once the donuts have cooled, dip the top into the pistachio and cardamom glaze. Immediately sprinkle with pistachio pieces; don't wait for the glaze to cool down, you really need to hurry at this stage.