In a large bowl or blender, combine the ripe apples, oats, eggs, honey (or maple syrup), baking powder, and salt. Blend until smooth, ensuring all ingredients are well incorporated and the mixture has a creamy consistency.

Once the batter is smooth, stir in additional whole oats for added texture. Use a spatula for gentle folding, ensuring that the oats are evenly distributed throughout the batter.

Preheat your oven to 180°C (350°F). Grease a smaller baking pan with cooking spray or a light coating of oil. Pour the batter into the prepared pan, spreading it evenly.

Place the baking pan in the preheated oven and bake for 20-30 minutes. To check for doneness, insert a toothpick into the center; it should come out clean.

Once baked, remove the cake from the oven and allow it to cool in the pan for about 10-15 minutes. Slice the cake into portions and transfer to an airtight container.