Preheat the oven to (350 degrees F / 177 degrees C).
In a large bowl, whisk eggs, add oil and milk, and combine well.
Add the cake mix and keep mixing until all combined.
Peel and shred apples. Add cinnamon powder, cardamom powder, and coconut flakes to shredded apples. Then, add shredded apples to the cake mixture and gently fold.
Add 1 teaspoon of flour to walnuts and mix. Then, add the walnuts to the cake mixture and fold again.
Transfer the cake batter to a prepared Bundt pan.
Bake for 35 minutes or until a toothpick inserted near the center comes out clean. Cool cake in a pan for 10 minutes. Loosen cake from the sides of the pan with a knife. Then, transfer the cake onto a wire rack. Let the cake cool completely. Slice the cake and sprinkle a little bit of cinnamon and powdered sugar. You can serve it with a cup of tea or coffee.