Preheat the oven to 350 degrees F (175 degrees C). Lightly grease a 9x5-inch loaf pan.

Stir together apples, sugar, and oil in a large bowl. Add egg; mix well. Sift flour, baking powder, baking soda, and cinnamon in a separate bowl. Stir flour mixture into wet ingredients until dry ingredients are moist. Stir in cranberries and walnuts. Spread batter into the prepared pan.

Bake in the preheated oven until a toothpick inserted into the center of loaf comes out clean, 35 to 45 minutes.