Marshmallow Slice with Biscoff and Caramel

Biscoff cake and cookies with caramel sauce - a triumphant flavor combination.  A contrast of moist cake, airy marshmallow and crunchy cookies - all combined, create a Gold Medal dessert!

I'm rather lukewarm about marshmallow. Sure, it's great in an occasional s'more but I had never made marshmallow myself and so when challenged to create a dessert called a "Marshmallow Slice", which I had never encountered, I was not enthused.

Can I "flip-flop" now? I am a big fan of marshmallow and find it easy to make and I love this Biscoff Caramel Marshmallow Slice dessert pictured above. Amazed to be amazed, the marshmallow is so pillowy and light, the Biscoff cookie cake and Biscoff butter infuse their beautiful spices and the rich caramel sauce melds it all together. The sliced almonds on the top? Why not? Doesn’t that sound like a symphony in which you’d like to play a part? Try a slice - it's so nice!

Biscoff & Caramel Marshmallow Slice

For the Biscoff Cake

1 cup plus 3 tablespoons all purpose flour

2 tablespoons cornstarch

1/4 teaspoon baking soda

1 teaspoon baking powder

1/4 teaspoon salt

1 teaspoon ground cinnamon

1/4 cup butter at room temperature (1/2 stick)

1/4 cup vegetable oil

2/3 cups soft light brown sugar - firmly packed

2 medium eggs - room temperature

1/3 cup Biscoff Cookie Butter (smooth) - also called Cookie Spread or Speculoos butter

1 1/2 teaspoons vanilla extract

2/3 cups buttermilk - room temperature

For the Caramel Marshmallow:

1 ½ cups water

6 teaspoons plain powdered gelatin (such as Knox)

2 1/3 cups granulated sugar

2 tablespoons light corn syrup

1 teaspoon vanilla extract

¾ cup caramel sauce, room temperature (purchased or home made)

For Marshmallow Slice Assembly:

12 plain Biscoff cookies, crushed to fine crumbs in food processor

1/2 cup Biscoff or Speculoos Cookie Butter

1/3 cup Caramel Sauce

1/3 cup toasted sliced almonds

For Caramel Sauce: If using homemade caramel, make that first. Cool to room temperature before using. (See Recipe under Persnickety notes.)

To Make the Biscoff Cake:

-Preheat oven 350°F. Prepare a 9 inch square baking pan as follows: -Spray a baking pan with cooking spray, then line with parchment paper by laying two 14 inch strips across the bottom and up the sides, with a bit of the paper hanging over the edges of all sides. Spray paper with cooking spray.

-In a bowl, stir together flour, cornstarch, baking soda, baking powder, salt and ground cinnamon. Using a whisk or fork, mix until well combined. Set aside.

-In a large mixing bowl, place butter, vegetable oil and light brown sugar. Using an electric mixer (hand or stand mixer) cream together for 2 minutes until light and creamy. Add in eggs one at a time, mixing about 30 seconds between each addition

-Add in Biscoff Cookie Butter and vanilla and mix until well combined.

-Using a rubber spatula or whisk, add half of your premixed dry ingredients to your wet mixture, and gently fold it in until just combined. Then add in the buttermilk and fold until just combined. Finally, add in the remaining dry ingredients and gently fold until just combined. Do not overmix.

-Pour the batter into the prepared baking pan and distribute evenly then level out the top. Give the pan a gentle rap on the counter to remove any air bubbles. Bake for 30 - 35 minutes or until a toothpick comes out clean or with a few moist crumbs on it.

-Allow the cake to cool in the baking pan completely before proceeding with recipe. Set aside while you make the marshmallow mixture. Place Biscoff Cookie Butter for 10 - 15 seconds in the mircrowave to make it spread more easily then spread 1/2 - 2/3 cups Biscoff Cookie Butter over the top of the cooled cake by working gently.

*Be sure the cake is baked and cooled before starting the marshmallow as it sets up very quickly.

To make the Caramel Marshmallow:

-Pour 1/2 cup of water into the bowl of a stand mixer fitted with a whisk attachment, then sprinkle the gelatin over the top and let it sit to soften.

-Place the remaining water, sugar and corn syrup into a medium saucepan (stainless steel, preferred). Stir together briefly before it starts to boil. Set a candy thermometer into the pan and place it over medium-high heat then bring to a boil. (Once the mixture starts to boil, discontinue stirring.)

-Once the mixture reaches 260F on the thermometer (about 10-15 minutes), remove from heat and let the boil subside. With the mixer running on low, pour the sugar syrup into the gelatin mixture in a thin stream, mixing until combined. Increase the speed to high and beat for 8 - 10 minutes until white and tripled in volume. It’s done when you can see strings of marshmallow pulling away from the sides.

-Add 1/2 cup of the room temperature caramel sauce and vanilla to the marshmallow and beat just to combine.

-Using a rubber spatula sprayed with cooking spray, scoop and spread half the marshmallow onto the Biscoff spread on the baked cake layer in the pan, nudging it out to the edges, then use slightly damp fingers to gently level marshmallow out. It will be starting to set so work as quickly as you can.

-Drizzle 1 ½ tablespoons of caramel over the surface of the marshmallow, then drag a knife through the marshmallow a few times to create a swirl pattern.

-Spread the remaining marshmallow on top. Nudge it out again then drizzle over another 1 ½ tablespoons of caramel and swirl it again with the knife.

To Complete Marshmallow Slice

-While the marshmallow is still warm spread Biscoff cookie crumbs and almond slices over the top. Let sit at room temperature at least 3 hours and up to 8 hours (or more) to firm up and make it easier to slice.

-Cut into slices or squares with a knife or pastry cutter, sprayed with cooking spray to make it easier. Cover left overs loosely with foil and let sit at room temperature for up to 2 days. Makes 10 - 12 servings.

Use damp fingers to nudge and spread warm marshmallow over the top of the cooled cake.

Drizzle caramel over the top of each marshmallow layer.

Swirl the caramel into the marshmallow by dragging a knife through it to create a swirling pattern.

Sprinkle toasted almonds and crushed Biscoff Cookies over the top layer of marshmallow.

Cut in slices, squares or bar shapes to serve.

Swirls of Caramel and Biscoff cookie crumbles with a few toasted almonds finish them off!

Pillowy marshmallow swirled with caramel pairs perfectly with the Biscoff cake and cookies.  A winner of a dessert!

PERSNICKETY NOTES:

*The Caramel: There are some excellent store-purchased caramel sauces available including brands such as Mrs. Richardsons and Smuckers (salted or not, as you prefer). If you would rather make your own and have lots leftover to keep in the fridge, use the following easy caramel recipe:

My Favorite Caramel Sauce:

1/2 cup butter
1 cup white karo syrup
1 cup brown sugar
1 can sweetened condensed milk
1 tsp. vanilla extract
-In a heavy bottomed, large saucepan, melt butter. Stir in karo syrup, brown sugar and sweetened condensed milk. Over medium-high heat, stir ingredients until sugar is melted and mixture is smooth. Continue stirring constantly until mixture comes to a boil. Lower heat slightly to medium and continue cooking and stirring another 5 minutes. Remove from heat and stir in vanilla. (If you prefer salted caramel, stir in 1/4 teaspoon “fleur de sel” or other coarse salt.). Let cool to room temperature. (If caramel sauce becomes too thick, heat it up slightly before use.) Makes 2 cups sauce.

*The Biscoff Cookie Butter:
I prefer to buy mine already made, (favorite brands, Lotus Biscoff Cookie Butter, or Trader Joe’s Speculoos Cookie Butter Spread) but if you would like to try to make your own, follow the recipe below:

Cookie Butter

6 ounces speculoos cookies (Dutch Windmill biscuits or Biscoff cookies) 1/4 cup brown sugar 1/2 cup evaporated milk 2 teaspoons salted butter 1 teaspoon lemon juice ¼ teaspoon ground cinnamon

*Pop speculoos or Biscoff cookies and brown sugar in a blender or food processor and give them a quick spin until nicely crushed and blended. Next pour in evaporated milk and give it all another good spin for about a minute.

*Finally, add butter, lemon juice and ground cinnamon and give everything another good pulse. The resulting mixture should be smooth, glossy, and near irresistible. Good luck and enjoy your speculoos adventures!

*The Cake: If you are looking for a short-cut, you can use your favorite cake mix. Spice cake would be ideal but a vanilla or golden cake mix would do nicely. (Resist using the stronger flavors of chocolate, lemon, strawberry - etc.) You want the Biscoff and Caramel flavors to play center stage in this dessert. You will use just half of the butter created from the cake mix. Cook up the rest of the batter as cupcakes for the kiddies!