Apple cake is a quick, easy dessert with great staying power. The moistness of the fruit prevents the cake from drying out, which makes this a perfect make-ahead recipe. The cake is delicious plain, but you wouldn't go wrong with a dollop of whipped cream or a puddle of crème Anglaise alongside!
Here we use white whole wheat flour, an option that's much lighter than traditional whole wheat flour and healthier than all-purpose flour — but you can substitute white flour or even whole wheat pastry flour if you wish.
Position a rack in the middle of the oven and preheat to 350 degrees F. Generously butter the sides and bottom of a 9-inch cake pan and set aside.
Place the sugar and butter in a large bowl and beat until combined. Beat in the egg until the batter is smooth. Stir in the diced apples.
In another bowl, whisk together the flour, cinnamon, nutmeg, baking soda and salt. Add the dry mixture to the apple batter, mixing just until combined. Transfer the batter to the prepared cake pan.
Bake until the cake is set, golden brown, and the edges have pulled away from the sides of the pan, 40 to 45 minutes. Let the cake cool on a wire rack for at least 15 minutes before turning it out onto a cake platter. Serve plain or with whipped cream, crème Anglaise or custard. The cake will keep, tightly covered, for up to 3 days.