Blend the soaked apricots (at least 30 minutes in hot water) into a paste.
Add oat flour, ground walnuts, baking powder, plant-based milk, agave syrup, coconut oil, and cinnamon, then blend into a thick batter.
Gently fold in the grated apple.
Spread the mixture evenly into a baking dish (18 × 30 cm / 7 × 12 in) lined with parchment paper.
Bake at 200 °C (390 °F) for about 20 minutes, then let cool completely.