Prep: Lower the oven rack one level below the middle of the oven. Grease a 9-inch springform pan and line the bottom with parchment paper.
Sugar batter: In a medium bowl, beat together the butter and sugar with an electric mixer.
Flour mix: Add the flour to the bowl and mix until combined.
Assemble: Press the mixture firmly into the bottom of the pan.
Cream cheese mixture: Beat the cream cheese, sugar, egg, and vanilla until smooth. Pour the filling over the base.
Apples: Toss the apples with sugar and cinnamon and spoon over the cream cheese mixture.
Nut topping: Sprinkle with sliced almonds. Cover the pan with foil.
Bake: Bake at 425°F for 15 minutes, then reduce the oven temperature to 400°F, remove the foil, and continue cooking for an additional 20-25 minutes.
Serve: Cool, then carefully remove the sides of the pan.Optional: Sprinkle with powdered sugar before serving.