Lemon Squares

1 package lemon cake mix w/pudding in the mix
1/2 cup butter, softened
1 egg
1 can sweetened condensed mil
Juice of 2 lemons

Preheat oven to 350 degrees.  Grease a 13x9 pan. In a bowl,
mix together the cake mix, butter and egg.  Spread into greased
pan.  In a separate bowl, mix together the sweetened condensed milk
with the lemon juice. Pour over cake mixture. Bake for 25 minutes.
Cool and cut into squares. Sprinkle with powdered sugar, if desired.