Prep the pan and oven: Heat the oven to 350°F (175°C). Grease a 9-inch springform pan or a 9-inch cake pan and line the bottom with parchment.

Prep the apples: Peel, core, and slice the apples about 1/4 inch thick. Toss them with lemon juice, half the cinnamon (about 3/4 teaspoon), and 1 tablespoon sugar. Set aside.

Cream the butter and sugars: In a large bowl, beat the softened butter with granulated and brown sugar until light and fluffy, about 2–3 minutes.

Add eggs and flavorings: Beat in the eggs one at a time. Stir in the vanilla and lemon zest. Mix just until combined.

Combine dry ingredients: In a separate bowl, whisk flour, baking powder, salt, the remaining cinnamon, and nutmeg.

Make the batter: Add the dry ingredients to the butter mixture in two additions, alternating with the milk or sour cream. Mix on low just until smooth. Do not overmix.

Assemble: Spread about two-thirds of the batter into the pan. Arrange half the apples over the batter. Spoon the remaining batter over the apples and gently spread. Top with the remaining apples in a simple pattern.

Bake: Place the pan on the middle rack and bake for 45–55 minutes, until the top is golden and a toothpick comes out clean or with a few moist crumbs.

Cool: Let the cake cool in the pan for 15 minutes. Run a knife around the edge, then release the springform or turn out onto a rack. Cool completely.

Finish and serve: Dust with powdered sugar before serving, if you like. Serve slightly warm or at room temperature.