Preheat the oven to 350°F. Spray a 13 x 9 inch baking dish with cooking spray.
Press the sugar cookie dough evenly onto the bottom of the baking dish. Press white chocolate chips and almonds into the dough.
Bake for 15 minutes. The crust will puff up slightly. Set aside.
Use an electric mixer to whip together pie filling, sweetened condensed milk, eggs, lemon zest, lemon juice and vanilla. Whisk on medium speed for 2 minutes or until light and fluffy.
Spread filling evenly over crust. Place back into the oven to bake for 25-30 minutes or until the center is set when gently shaken.
Cool completely on a cooling rack. Chill for 3 hours.
Dust with powdered sugar just before serving. Serve with a dollop of sweetened fresh whipped cream, if desired.
Store leftovers in an airtight container chilled.