01 -
Preheat oven to 350°F and grease a square baking dish (8x8 or 9x9 inches) with butter or nonstick spray.
02 -
Slice apples thinly and discard the cores. Turn baking dish on its side and support with an oven mitt or kitchen towel to keep upright. Stack apple slices in baking dish until full. Lay baking dish flat once more.
03 -
In a medium bowl, whisk together the sugar, eggs, melted butter, milk, and vanilla extract. Add flour, salt, baking powder, and cinnamon and whisk to combine.
04 -
Pour batter over sliced apples and bake until golden brown, about 45 minutes.
05 -
Let cake rest 5 minutes, then invert onto a cutting board, and then invert once more onto a serving plate so the apple slices are facing up. Slice, serve, and enjoy!