Glazed Oat Milk Doughnuts With Streusel

Name: Glazed Oat Milk Doughnuts With Streusel
Ingredients: For the doughnuts:; 72 gram (6 Tbsp) aquafaba, or about 1/2 the liquid from 1 can of chickpeas, drained; 5 gram (2 tsp) ground flaxseed; 200 gram (1 cup) Planet Oat Original Oatmilk; 57 gram (1/4 cup) vegan butter or coconut oil, melted; 364 gram (3 cups) bread flour; 90 gram (3/4 cup) all-purpose flour; 4 gram (2 tsp) cardamom; 2 gram (1 tsp) cinnamon; 14 gram (1 tsp) kosher salt; 5 gram (1 1/2 tsp) quick-rise yeast; For the oat milk pastry cream:; 400 gram (2 cups) Planet Oat Original Oatmilk; 12 gram (1 Tbsp) vanilla extract or 1 vanilla bean split and insides scraped with a small paring knife; 120 gram sugar; 60 gram (1/2 cup) cornstarch; 60 gram (4 Tbsp) cold vegan margarine, cut into cubes; 26 gram (2 Tbsp) brown sugar; 12 gram (2 Tbsp) rolled oats; Pinch of salt; 28 gram (2 Tbsp) cold vegan butter or margarine; For the glaze:; 223 gram (2 cups) powdered sugar; 60 gram (1/4 cup) Planet Oat Original Oatmilk; Zest and juice of 1/2 lemon (optional, but delicious)