Preheat your oven to 350°F (175°C). Lightly grease a cake pan and set aside. If your walnuts aren’t toasted yet, spread them on a baking sheet and toast in the oven for about 8 minutes until fragrant, then let cool and chop roughly.
In a large mixing bowl, whisk together the sifted flour, ground cinnamon, baking powder, and salt to combine evenly.
In another bowl, cream the softened butter and sugar together until the mixture is light and fluffy, with a slightly pale color and a gentle aroma of sweetness.
Add the eggs one at a time to the butter mixture, whisking well after each addition to incorporate air and create a smooth, glossy batter.
Stir in the vanilla extract, then gradually fold the dry ingredients into the wet mixture, just until combined—be careful not to overmix, so the batter stays tender.
Gently fold in the sliced apples and chopped toasted walnuts into the batter, distributing them evenly without overworking the mixture.
Pour the batter into your prepared cake pan, smoothing the top with a spatula for an even surface. The batter will be thick but spreadable.
Bake in the preheated oven for about 40 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.
Once baked, remove the cake from the oven and let it cool in the pan for 10 minutes, then transfer to a cooling rack to cool completely, allowing flavors to set and moisture to stabilize.
Slice the cake once fully cooled. The slices should reveal tender apple layers, speckled with crunchy walnuts, with a warm, inviting aroma.
Serve the apple walnut cake on its own or with a dollop of whipped cream or a dusting of powdered sugar for added sweetness and presentation.
