Preheat the oven to 350 degrees F. Spray (3) 9-inch round cake pans with baking spray.
In a large bowl, combine cake mix, eggs, milk ,and butter.
Evenly divide the batter and bake for 25-30 minutes. Cool completely.
For the Nougat
In a large saucepan, melt butter over medium low.
Whisk in the sugar and evaporated milk. Bring to boil.
Reduce to simmer, and cook for 3-5 minutes.
Remove from heat and whisk in the marshmallow fluff, peanut butter, and vanilla until smooth.
Fold in the peanuts. Cool.
For the Frosting
Cream butter, salted caramel, and cream cheese. Stir in powdered sugar a little at a time until you reach your desired consistency.
For the Ganache
Pour the chocolate chips into a medium bowl. In a small saucepan, heat milk until simmering.
Pour the heavy whipping cream over the chocolate chips and allow to sit for 1 minute before stirring.
Putting It All Together
First Layer: Pipe a thick ring of frosting around the edge of the cake. Scoop around ¾ cup of the nougat into the center.
Second Layer: Place on top of the first layer and repeat.
Third Layer: Place the third layer on top. Frost top and sides of cake. Pipe frosting using a star tip is desired.
Use a squeeze bottle to drip ganache down the sides.
Garnish with snickers and peanuts if desired.
Notes
Ingredient Notes and Shopping Tips
Cake Mix: Use your favorite. I like Duncan Hines Triple Chocolate.
Butter: Use butter instead of oil in your cake for a richer flavor.
Milk: Use milk instead of water for a moist and tender crumb.
Evaporated Milk: Make sure you buy evaporated, not sweetened condensed milk. Evaporated milk is shelf-stable milk that has had around 60% of its water removed.
Marshmallow Fluff: This light, fuffy ingredient makes the perfect nougat (try it on Smores too). Look for it in the baking aisle near the chocolate chips.
Peanut Butter: Use smooth peanut butter for the best results. Also, avoid natural nut butter.
Salted Caramel Sauce: I used Ghiradelli. Look for it near the ice cream cones.
Tips
Do Not Over Bake: Bake until a toothpick inserted in the center comes out clean or with just a few moist crumbs.
Flat Cakes: Use a cake leveler to get flat cake layers for easy stacking.
Smooth Frosting: Use a spinning cake stand and an offset spatula for a super smooth finish every time.
Easy Transport: Use a cake board until your bottom layer to make moving your cake easier.
Make Ahead: Make the components up to a day in advance. Assemble the day of.