Preheat oven to 375 degrees.
Line a 12 cup muffin tin with paper liners or grease well, if using loaf pans, grease well.
In a large bowl, whisk together the dry ingredients: flour, oatmeal, baking powder, baking soda, cinnamon, and salt.
In a medium bowl, whisk the wet ingredients: eggs, buttermilk, honey, oil or melter butter, and vanilla until smooth and well combined.
Pour the wet mixture into the dry ingredients and stir gently with a spatula or wooden spoon until just combined ( a few lumps are okay--don't over mix to keep tender).
Fold in the diced apples, raisins, cranberries, and chopped walnuts until evenly distributed.
Divide the batter evenly among the muffin cup, if using loaf pans, divide evenly between the two pans. Optional: a bit more cinnamon on top before baking for extra aroma.
Bake for 18--24minutes if muffins, the tops should be golden and spring back lightly when touched.
Bake for 30 minutes if loaf, or until a toothpick inserted in the center comes out clean or with a few moist crumbs
Let cool in the tin for 5 minutes, then transfer to cooling rack to cool completely (or enjoy warm).
If loaves, cool longer or until the edges can be moved away from the sides. turn out onto cutting board for slicing.