A few notes:

The recipe yields one 8×8 cake. For the picture I sliced the cake in half for two cake loaves.
Variations: Change out the graham cracker for chocolate ones. Switch out the peanut butter with Nutella for a Nutella Icebox Cake. For a Twix version replace the peanut butter with some homemade caramel or melt down some Kraft caramels for a caramel pudding and then top with chopped Twix instead of Snickers.
Cake can be fully assembled and kept in freezer or refrigerator for up two days.
I froze my cake for a more ice cream like texture and it also makes for nice clean slices.

Snickers Icebox Cake

Makes one 8×8 cake or two 4×8 cake loafs

Ingredients:

16 whole crackers

Pudding

2/3 cup cornstarch
1 cup granulated sugar
Pinch of salt
6 cups cold whole milk
1 tablespoon pure vanilla extract
3/4 cups dark chocolate, chopped
3/4 cups creamy peanut butter

Caramel sauce

1 cup sugar
6 tablespoons water
4 tablespoon butter
¼ c heavy cream

Ganache pouring sauce

2/3 cups dark chocolate
1 tablespoons heavy cream
4 tablespoons powdered sugar, sifted
4-5 tablespoons water, warm

12-14 mini Snickers, chopped