Blueberry Cake Donuts

Preheat the oven to 350 degrees. Grease a donut pan and set aside.
In a small bowl whisk together the all-purpose flour, baking powder, salt and ground cardamom (if using). Set aside.
2 cups (250 g) all-purpose flour, spooned and leveled, 1 tbsp baking powder, 1/2 tsp salt, 1 tsp ground cardamom (optional)
Add the blueberries to a small, separate bowl and sprinkle flour over them. Stir to coat, then set aside. (This helps the berries not sink to the bottom while baking.)
1 1/2 cups / 9 oz (255 g) fresh blueberries, 1 tbsp (8 g) all-purpose flour, spooned and leveled
In a large bowl, whisk together the melted butter, granulated white sugar, eggs, vanilla, sour cream, and milk.
1/2 cup (112 g) unsalted butter, melted, 1 cup (200 g) granulated white sugar, 2 large eggs, at room temperature, 1 tsp vanilla, 1/2 cup (122 g) sour cream, at room temperature, 1/2 cup (120 ml) whole milk, at room temperature
Add the dry ingredients to the wet ingredients and whisk just until combined
Add in the blueberries and gently fold them into the batter with a rubber spatula.
Add the batter to a piping bag and cut off the tip. Pipe the batter into the prepared donut pan until each well is three-quarters full.
Bake the donuts for 11-12 minutes. Let them cool for 10 minutes in the pan then turn them out on a wire rack to cool completely. Then repeat with the rest of the batter until all the donuts are baked.

To make the blueberry vanilla glaze, add powdered sugar, blueberry jam, vanilla and milk to large mixing bowl, big enough to easily dip the donuts into. Whisk until smooth. (Start with 2 tbps of milk and add more as necessary until the right consistency is reached.)
2 cups (260 g) powdered sugar, 2 tbsp blueberry jam, 1 tsp vanilla, 2-3 tbsp milk
Dip each donut into the glaze and return each to the wire rack. Let the icing set on the donuts, about 30 minutes, then serve!