Biscoff Butterscotch Marshmallow Sandwich Cookies
Chewy Biscoff-infused cookies and a dreamy butterscotch marshmallow buttercream come together in a sandwich cookie that’s sweet, tender, and guaranteed to disappear fast.
Servings: 12 sandwich cookies
Ingredients
BISCOFF COOKIES
- 1 cup + 2 Tablespoons (135g) all-purpose flour be sure to measure properly
- 10 Biscoff cookies1 crushed into a fine crumb, about ½ cup
- 1 teaspoon cornstarch
- ½ teaspoon baking soda
- ¼ teaspoon baking powder
- ½ teaspoon salt
- ½ cup (113g) unsalted butter softened to room temperature
- ¾ cup (150g) firmly packed light brown sugar
- 1 large egg at room temperature
- 1 teaspoon vanilla extract
- ½ cup (120g) Biscoff cookie butter1
BUTTERSCOTCH MARSHMALLOW FROSTING
- 4 ounces (113g) butterscotch chips
- ½ cup (113g) unsalted butter softened to room temperature
- 2 ounces (57g) marshmallow fluff
- 1 to 2 Tablespoons (15-30mL) room temperature water2
- 1 and ¾ cups (210g) powdered sugar
- ¼ teaspoon salt
Need to keep track of your ingredients?Check out my Printable Ingredient List!
Instructions
BISCOFF COOKIES
- Preheat the oven to 350°F (177ºC). Line a large baking sheet with parchment paper or a silicone baking mat. Set aside.
- In a medium size bowl, combine the flour, crushed Biscoff cookies, cornstarch, baking soda, baking powder, and salt. Whisk together until everything is combined, then set aside.1 cup + 2 Tablespoons (135g) all-purpose flour, 10 Biscoff cookies1, 1 teaspoon cornstarch, ½ teaspoon baking soda, ¼ teaspoon baking powder, ½ teaspoon salt
- In a large bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, cream together the the butter and brown sugar on medium-high speed until light and fluffy, about 2-3 minutes. Add the egg and vanilla extract and beat again until everything is combined.½ cup (113g) unsalted butter, ¾ cup (150g) firmly packed light brown sugar, 1 large egg, 1 teaspoon vanilla extract
- Add the cookie butter and mix until combined. Turn off the mixer, scrape down the sides and bottom of the bowl, then beat on low until everything is incorporated.½ cup (120g) Biscoff cookie butter1
- Turn the mixer speed to medium, then slowly add the flour and blend until no flour pockets remain. Cover the cookie dough and allow it to rest for 10 minutes.
- Using a cookie scoop (I use this #50 cookie scoop for all of my standard size cookies), drop rounded balls of dough onto the prepared baking sheet. Use your hands to roll them into a smooth ball. The dough will be soft but should not be sticky.
- Bake the cookies for 8-10 minutes just until edges are just set. The centers will look underdone. Working quickly but carefully, use a large round cookie cutter or the rim of a glass or mug to reshape hot cookies. This will tuck in any edges that got thin and make the cookies uniform in size. Allow to rest on the baking sheet for 10 minutes before transferring to a wire cooling rack to cool completely before making sandwiches.
BUTTERSCOTCH MARSHMALLOW FROSTING
- In a small saucepan over medium heat or in a microwave safe bowl in the microwave, melt the butterscotch chips until smooth. Remove from heat and allow to cool for 10 minutes4 ounces (113g) butterscotch chips
- In a medium size bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, combine the cooled butterscotch mixture, butter, and marshmallow fluff, and beat on medium-high speed until smooth, about 2-3 minutes. Add water, starting with just 1 Tablespoon, and blend on medium speed until combined.½ cup (113g) unsalted butter, 2 ounces (57g) marshmallow fluff, 1 to 2 Tablespoons (15-30mL) room temperature water2
- Turn the mixer down to low and slowly add the powdered sugar. Increase mixer speed to medium and beat until completely combined, scraping down sides as needed. Add the salt, taste, and add more salt if needed. Turn off the mixer and use a spatula to stir the buttercream by hand to remove air bubbles and make it smooth and creamy. This usually takes about 3-5 minutes.1 and ¾ cups (210g) powdered sugar, ¼ teaspoon salt
ASSEMBLE THE SANDWICH COOKIES
- When you are ready to assemble the sandwiches, pair the cookies, bottom to bottom, with like-sized/shaped cookies as best as possible.
- Working with the bottom cookie of one pair at a time, add the frosting to a piping bag or use an offset spatula to spread frosting onto the bottom of the cookie. Leave about ½" border so you can "squish" the cookies together.
- Take the top cookie and press the bottom of the cookie onto the fresh frosting to make a sandwich. Press the cookies together gently so the frosting moves to the edges. Cookies can be served immediately, but in my opinion, they get better as they sit! Store filled gingerbread cookies covered tightly at room temperature for up to 5 days. Cookies freeze well, up to 3 months. Unbaked cookie dough balls freeze well, up to 3 months. Do not roll in sugar, allow to thaw in the refrigerator, then roll in sugar and bake as directed.
- Make ahead: you can make the cookies and/or frosting up to 2 days in advance. Store at room temperature covered tightly, then assemble when you are ready.
Video
Notes
- Biscoff brand: you can use any other brand of cookie butter that you prefer or can find. The Trader Joe's equivalent is Speculoos cookies and cookie butter spread.
- Room temperature water: it is imperative your water is at room temperature so it does not disrupt the texture of the melted butterscotch chips. You could also use cream or milk, but you must make sure it is not completely cold.
Nutrition Disclosure
All nutritional values are approximate and provided to the reader as a courtesy. Changing ingredients and/or quantities will alter the estimated nutritional calculations.
Serving: 1sandwich cookie | Calories: 497kcal | Carbohydrates: 71g | Protein: 4g | Fat: 22g | Saturated Fat: 12g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 5g | Trans Fat: 1g | Cholesterol: 55mg | Sodium: 278mg | Potassium: 60mg | Fiber: 1g | Sugar: 46g | Vitamin A: 510IU | Calcium: 28mg | Iron: 1mg
