Line a 8×8 baking pan with parchment paper or aluminum foil, lightly spray with cooking spray and set aside.
Combine melted butter, almond flour and sweetener. Mix well.
Pat crust into pan and bake for 6-7 minutes until lightly set and beginning to brown slightly. Allow crust to cool completely before adding the cheesecake layer.
Combine cream cheese, egg, egg yolk, powdered sweetener, vanilla, zest and lemon juice in a bowl and beat with an electric mixer until well combined.
Evenly spread the cheesecake filling over the cooled crust and bake 25-30 minutes, until a toothpick placed in the center comes out clean.