In a bowl, combine dry cake mix, dry instant pudding mix, eggs, sour cream, melted butter, vanilla and 1-1/4 cups milk.

Beat with an electric mixer on medium speed for 2 minutes.

Pour batter into a lightly greased 4 or 5 quart slow cooker.

Sprinkle dry cook & serve pudding mix over batter.

In a sauce pan over medium heat, heat remaining milk stirring often for 3 to 5 minutes; do not boil.

Slowly pour hot milk over pudding.

Cover and cook on high setting for 2 hours on low or 3.5 to 4 on low or until done.

Cake will set up as it stands.

Uncover and let cool for 15 minutes.

Sprinkle cake with remaining ingredients.

Let stand for 15 minutes or until marshmallows are slightly melted.

Spoon into dessert dishes.