
Peanut butter caramel, homemade marshmallow, chocolate ganache, and toasted peanuts layered on top of a buttery shortbread cookie crust.
Today I am taking two of my childhood favorites, fluffernutter and millionaire’s shortbread (a.k.a. Twix), and combining them into one decadently rich treat. All of the recipes below are fairly simple to make, and if followed in succession, they don’t seem to take up too much time.


Here are a few tips to help create these tasty treats. Poke the shortbread with a fork before baking, allowing the air to escape and keeps the crust from bubbling up. If you see any bubbles appear during baking, just poke it, and the crust should flatten out. The crust will brown slightly around the edges but will stay mostly white. It should feel solid to the touch when done.
The caramel will need to be stirred almost constantly while it is cooking to prevent clumping and burning. If you get a few clumps, don’t worry, it will still taste delicious. Once it is cooked, the caramel needs to be taken off the heat and allowed to cool for one minute before adding the peanut butter. If the caramel is cooled too long, it will begin to set, and the peanut butter will not melt into it. If this happens gently, heat the caramel until it is warm enough to melt the peanut butter, then pour onto the shortbread. The caramel can be poured directly onto the hot shortbread, but it will need to cool and set a bit before adding the marshmallow.


The marshmallow layer is probably the most temperamental. Make sure the gelatin has no clumps and is fully hydrated before adding the hot sugar. When heating the sugar, you can stir the mixture until it has dissolved, but do not stir it after it has come to a boil to prevent crystallization. The sugar must be heated to 240 degrees to ensure that it whips and sets up properly. Add the sugar in a slow, steady stream to allow it to cool slightly and keep it from overheating the gelatin. If the gelatin gets too hot, it will lose its strength and will not set properly. Whip the mixture on high until it becomes ribbony and forms soft peaks. Spread it over the caramel with a lightly oiled offset spatula. The oil creates a barrier that keeps the sugar from sticking. If it begins to stick, just clean the spatula and add a little more oil.


The marshmallow will need to be refrigerated and allowed to set before adding the ganache. The chocolate is the easiest of the layers. Simply heat the cream and mix with the chocolate to melt. Smooth it over the marshmallow and add the toasted peanuts. Then comes the most difficult part, waiting for it to set up before you can slice and enjoy!

Cutting the bars directly from the fridge keeps the layers firm, making them easier to slice through. I like to trim off the uneven edges before slicing, but this is only for aesthetic appeal. Use a warm knife to cut the bars. The heat from the knife will allow it to cut through the chocolate without breaking. To do this, run the blade through hot water, and dry it off before each slice. The bars can be kept in the refrigerator but will be best served at room temperature.
Fluffernutter Millionaire’s Shortbread
Ingredients
Shortbread
- 1 1/2 cup flour
- 1/4 tsp salt
- 1/4 cup sugar
- 6 tbsp butter melted
- 1/2 tsp vanilla
Peanut Butter Caramel
- 1/2 cup brown sugar
- 1/4 cup corn syrup
- 7 ounces sweetened condensed milk 1/2 can
- 1 tbsp butter
- 1/4 tsp salt
- 1/4 cup cream
- 3 tbsp peanut butter
Marshmallow
- 2 tsp gelatin powdered
- 1/8 cup water
- 6 tbsp 1 tsp sugar
- 1/8 cup corn syrup
- 1/8 cup water
- 1/4 tsp salt
- 1/4 tsp vanilla
Ganache
- 4 ounces cream
- 4 ounces semi-sweet chocolate chopped
- 1/4 cup peanuts toasted and chopped
Instructions
Shortbread
- Preheat the oven to 350 degrees. Line a 7 or 8-inch square pan with parchment. Mix the dry ingredients in a bowl. Mix in the melted butter and vanilla until well combined. Press the dough into the pan and poke with a fork. Bake for 25-30 minutes.
Peanut Butter Caramel
- While the shortbread is baking, add all of the ingredients except peanut butter to a small pan. Heat over high heat, stirring frequently, until it reaches 236-239 degrees. Remove from heat, wait 1 minute, and stir in the peanut butter. Pour on top of the baked shortbread and smooth over the top. Allow the caramel to come to room temperature before adding the marshmallow.
Marshmallow
- Pour 1/8 cup of water into a mixing bowl. Sprinkle the gelatin over the water and allow it to hydrate. In a small pan mix the sugar, corn syrup, salt, and water. Heat over high heat until the mixture reaches 240 degrees. Take off the heat. Begin mixing your gelatin mixture with a whip attachment. Slowly pour the sugar mixture down the side of the mixing bowl in a thin steady stream. Whip the mixture until light and fluffy. It will ribbon and have soft peaks. Spoon the marshmallow over the caramel and smooth the top. Refrigerate for 30 minutes before adding the chocolate.
Ganache
- In a small pot heat the cream until a simmer. Remove from heat and add the chopped chocolate. Stir until smooth. Pour the chocolate on top of the marshmallow and smooth over. Sprinkle with toasted chopped peanuts and refrigerate for a couple of hours to set up. Remove the shortbread from the pan and cut it into 14 pieces. Store and serve at room temperature.