Preheat oven to 350°. Spray a 9″x 13″x 2″ baking pan with nonstick cooking spray.
Combine flour, oats, cashews, 1 cup sugar, and baking soda in a large bowl. Stir in melted butter. Reserve 1 & 1/2 cups of mixture for topping. Press remaining mixture into bottom of prepared pan. Bake for 12-15 minutes or until lightly browned. Set pan on wire rack to cool.
Beat cream cheese and 3/4 cup sugar at medium speed with an electric mixer. When mixture is creamy, add eggs, one at a time, beating well after each addition. Add lemon juice and vanilla extract. Beat until combined.
Spread apple butter over cooled crust. Spread cream cheese mixture over apple butter. Top with reserved oat mixture. Bake 35-40 minutes or until cream cheese layer is set. Cool completely before cutting into bars.