Prepare cake batter as directed on package.
Pour into a greased 6 quart crock pot.
Pour milk, water and lemon juice into a large bowl.
Add dry pudding mix.
Beat with a wire whisk for 2 minutes or until soft set.
Pour gently over the batter making sure the pudding is evenly distributed.
Cook on low for 2 1/2 - 3 1/2 hours (depending on how hot your crock pot cooks) or until a toothpick inserted in the center of the cake comes clean.
Turn crock pot off and cool for 15 minutes.
Sprinkle with powdered sugar.