Peel and core the apples, then slice them into thin, even pieces. Set aside.
In a large mixing bowl, whisk together the flour, sugar, cinnamon, nutmeg, and salt until well combined.
In a separate bowl, beat the eggs until slightly frothy, then add the melted butter and vanilla extract, mixing well.
Pour the wet mixture into the dry ingredients and gently fold until just combined—be careful not to overmix.
Gently fold the sliced apples into the batter, distributing them evenly to ensure a moist, apple-filled cake.
Pour the batter into a greased 9-inch round cake pan, smoothing the top with a spatula for an even surface.
Sprinkle the remaining sugar evenly over the top of the batter for a sweet, crunchy topping.
Bake in a preheated oven at 350°F (175°C) for about 40 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.
Remove the cake from the oven and let it cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Slice and serve the cake warm or at room temperature, enjoying the tender crumb with a hint of spice and the crisp topping.
