Preheat the oven to 350°F (176°C). Grease the sides of an 8-
or 9-inch (20.5- or 23-cm) round cake pan with a little oil or vegan butter and
line the bottom with a circle of parchment paper.
In a large mixing bowl, combine the flour, ground flaxseeds,
rolled oats, sugar, baking soda, baking powder, cinnamon and salt; then stir
well.
In a separate bowl, combine the vinegar, applesauce, yogurt
and vanilla and stir together.
Pour the wet ingredients into the dry and stir gently to
combine. Don’t overmix. The batter will be very thick. Fold the blueberries
into the batter.
Spoon into the prepared cake pan and sprinkle with a few
more oats and blueberries. Bake for about 40 minutes, or until a toothpick
inserted into the middle of the cake comes out clean. Remove from the oven and
leave in the pan for 10 minutes. Then remove the cake, peel off the baking
parchment circle and allow to cool completely on a cooling rack.
Once the cake is cool, prepare the frosting: Put the
powdered sugar in a small bowl. Add the yogurt gradually, a tablespoon (15 g)
at a time, stirring really well between each addition to smooth it out. Stop
when you have a thick but drizzlable consistency.
Drizzle all over the top of the cake, allowing some to spill
over the sides.
Store, covered, in the fridge. It will keep for 4 to 5 days.