Creating this incredible Apple Cake is a breeze when you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour a 9×13 inch baking pan.
2. Mix Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Set aside.
3. Cream Butter and Sugar: In a large mixing bowl, beat the softened butter and granulated sugar together until light and fluffy, about 3-5 minutes.
4. Add Eggs and Vanilla: Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract until well combined.
5. Combine Mixtures: Gradually add the dry ingredient mixture to the wet mixture, mixing just until combined. Do not overmix.
6. Fold in Apples and Nuts: Gently fold in the diced apples and chopped nuts (if using) until evenly distributed throughout the batter.
7. Pour Batter into Pan: Pour the batter into the prepared baking pan, spreading it evenly.
8. Bake: Place in the preheated oven and bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
9. Cool the Cake: Remove from the oven and allow the cake to cool in the pan for about 15 minutes. Then, transfer it to a wire rack to cool completely.
10. Dust with Powdered Sugar: Once cooled, dust the top with powdered sugar for an elegant finish if desired.

Following these steps will ensure that your Apple Cake turns out perfectly every time. The combination of flavors and textures will surely impress anyone who has the pleasure of enjoying a slice!