preheat oven to 400°. For crust, mix flour, melted butter, sugar and nuts in a bowl, using your hands or a spatula. pat on bottom and up the sides of a 9 inch springform pan.
For filling, beat cream cheese, 1/4 cup of the sugar, egg and vanilla in a medium bowl with a handheld mixer until smooth. Pour into prepared crust. Using the same bowl, toss the Apple slices with the pumpkin pie spice, the remaining 1/4 cup sugar and lemon juice.
Attractively arrange Apple slices in a circle on top of filling. Pour any juice left from the fruit on top. Bake for 20 to 25 minutes or until cake tester inserted in center comes out clean. Remove to a wire rack to cool in pan for 20 minutes, then remove the sides and serve. Makes eight servings.