2In the bowl of a mixer, combine cake mix and lemon pie filling. Beat on medium speed until just combined.
3Spread in an ungreased 10x15x1 inch jelly roll pan. Bake for about 20 minutes or so, until puffy and top isn’t super sticky or gooey. Remove from oven and let cool.
4Make glaze: Whisk together lemon juice and powdered sugar. If it’s too thick, add a bit more lemon juice or some water. Too thin, add a bit more powdered sugar. Drizzle over bars and cut into squares.