Combine soy milk, water, dates, and flax seeds in a bowl.
Preheat the oven to 400 degrees F (200 degrees C).
Combine ground oats, brown sugar, baking powder, and cinnamon in a large bowl.
Combine the date mixture, applesauce, and vanilla extract in a blender. Blend until evenly mixed; pour into the bowl with the oat mixture. Stir until no dry spots remain. Fold in blueberries. Pour batter into a 12-cup muffin tin.
Bake in the preheated oven until tops spring back when lightly pressed, about 20 minutes. Let cool in the tin.