Step 1: Prepare the Ingredients

• Preheat your oven to 350°F (175°C).
• Grease a 9-inch round cake pan or a loaf pan with butter and dust with flour.
• Peel, core, and chop the apples into small bite-sized pieces.

Step 2: Mix the Dry Ingredients

• In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
• Set this aside while you prepare the wet ingredients.

Step 3: Cream Butter and Sugar

• In a large mixing bowl, beat the butter, granulated sugar, and brown sugar together until light and fluffy.
• Add the eggs one at a time, mixing well after each addition.
• Stir in the vanilla extract.

Step 4: Combine Wet and Dry Ingredients

• Add half of the dry ingredients to the wet mixture and mix gently.
• Pour in the buttermilk and mix until combined.
• Add the remaining dry ingredients and stir until just combined (do not overmix).
• Fold in the chopped apples using a spatula.

Step 5: Bake the Cake

• Pour the batter into the prepared cake pan and smooth the top.
• If using the topping, mix brown sugar, cinnamon, and nuts, then sprinkle over the batter.
• Bake for 40-45 minutes or until a toothpick inserted in the center comes out clean.

Step 6: Cool and Serve

• Let the cake cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.
• Slice and enjoy!