Name: Butterscotch Marshmallow Sandwich Cookies Recipe
Prep time: 20 min
Cook time: 10 min
Total time: 45 min
Cuisine: American
Ingredients: 1 cup + 2 Tablespoons (135g) all-purpose flour; 10 Biscoff cookies (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 butter; 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 water; 1 and ¾ cups (210g) powdered sugar; ¼ teaspoon salt

Print Recipe· 4.1 from 4 reviews

If you have a sweet tooth that’s always on the lookout for something nostalgic and irresistibly cozy, then this Butterscotch Marshmallow Sandwich Cookies Recipe is going to become your new obsession. Imagine soft, chewy cookies infused with the warm aroma of Biscoff and butterscotch, all sandwiched around a luscious, fluffy marshmallow frosting that melts in your mouth. Each bite delivers a perfect harmony of caramel-like sweetness and creamy texture, making these cookies the ultimate treat for sharing with friends, family, or just savoring with a cup of tea. Trust me, these are not your everyday cookies—they’re a celebration of flavor and comfort all wrapped up in a delightful sandwich cookie form.

Ingredients You’ll Need

The image shows a white marbled surface with various ingredients arranged neatly for baking. There is one large clear glass bowl filled with white flour on the left side. Above it are several brown Biscoff cookies stacked in a slightly messy pile. To the right of the cookies, a small clear bowl contains white baking soda and powder. A stick of pale yellow butter lies beside it. Below the butter, a jar of creamy brown Biscoff spread with a red lid sits on its side. Near the center, a white egg is placed next to small clear cups holding salt, cornstarch, and vanilla extract. A small white bowl with fluffy white fluff is nearby. Below, there is a white bowl filled with light brown sugar and a small bowl of golden butterscotch chips. Another white bowl filled with powdered white sugar completes the layout. All items are evenly spaced on the smooth white marbled background photo taken with an iphone --ar 4:5 --v 7

This recipe uses simple yet special ingredients that work together beautifully to create the rich, tender texture and captivating flavor profile of these cookies. Every component plays its role, from the finely crushed Biscoff crumbs adding subtle spice and crunch to the smooth cookie butter and creamy marshmallow fluff giving depth to the filling.

All-purpose flour (1 cup + 2 Tablespoons): Provides the sturdy yet tender structure of the cookies.
Crushed Biscoff cookies (about ½ cup): Adds a unique cinnamon-spiced crunch and amazing depth of flavor.
Cornstarch (1 teaspoon): Helps keep the cookies soft and delicate by reducing gluten formation.
Baking soda (½ teaspoon) & baking powder (¼ teaspoon): These leavening agents give a gentle rise for perfect texture.
Salt (½ teaspoon): Balances sweetness and enhances all the flavors.
Unsalted butter (1 cup, divided): Adds richness and keeps the cookies tender and moist. Make sure it’s softened for easy mixing.
Light brown sugar (¾ cup): Brings moisture and caramel notes for that soft chew.
Large egg (1): Binds the dough and lends structure.
Vanilla extract (1 teaspoon): Brightens the overall flavor with warm floral notes.
Biscoff cookie butter (½ cup): Infuses the dough with buttery, spicy sweetness unique to this recipe.
Butterscotch chips (4 ounces): Melted into the frosting for that golden toffee flavor.
Marshmallow fluff (2 ounces): The star of the sandwich filling, offering lightness and creaminess.
Powdered sugar (1 and ¾ cups): Sweetens and stabilizes the frosting for the perfect consistency.
Water (1 to 2 Tablespoons): Added to thin out the frosting just enough for spreading.

How to Make Butterscotch Marshmallow Sandwich Cookies Recipe

Step 1: Prepare the Dry Ingredients

Start by preheating your oven to 350°F (177ºC) and lining a baking sheet with parchment paper or a silicone mat to prevent sticking. In a medium bowl, whisk together all-purpose flour, crushed Biscoff cookies, cornstarch, baking soda, baking powder, and salt until well combined. This mix forms a flavorful, spiced base that will give the cookies their signature texture and taste.

Step 2: Cream the Butter and Sugars

Using a stand mixer or handheld mixer, beat the softened butter and light brown sugar on medium-high speed until the mixture is light and fluffy, roughly 2 to 3 minutes. This step is key to ensuring tender cookies with a delightful chew. Adding the egg and vanilla next, continue mixing until fully incorporated for that subtle vanilla warmth.

Step 3: Add Cookie Butter and Dry Ingredients

Blend in the Biscoff cookie butter until fully combined, scraping down the bowl as needed. Then, on medium speed, gradually add the dry mixture so everything melds into a smooth dough. Cover the dough and let it rest for about 10 minutes to allow the flavors to marry and the cornstarch to fully hydrate for better texture.

Step 4: Shape and Bake the Cookies

Using a cookie scoop or your hands, form even balls of dough and place them on your prepared baking sheet. The dough is soft but not sticky, so rolling into smooth balls is fairly easy. Bake for 8 to 10 minutes just until the edges begin to set but centers remain slightly underbaked—this guarantees a soft, chewy bite. While still warm, reshape the cookies using a round cutter or glass rim for uniform size, then cool completely on a wire rack.

Step 5: Make the Butterscotch Marshmallow Frosting

Gently melt the butterscotch chips in a small saucepan or microwave until smooth, then let cool for 10 minutes. Beat the melted butterscotch with softened butter and marshmallow fluff until creamy and smooth. Slowly add powdered sugar and a pinch of salt, blending until a luscious, pipeable frosting forms. Add a tablespoon of water as needed to achieve the perfect spreading consistency.

Step 6: Assemble the Sandwich Cookies

Match cookie pairs of a similar size and shape. Pipe or spread the frosting onto the bottom side of one cookie, leaving a small border so the filling can spread evenly when pressed together. Gently press the top cookie onto the frosting, creating an irresistible sandwich. Allow them to rest and set briefly for the flavors to meld beautifully, though they can be enjoyed immediately if patience isn’t on your side!

How to Serve Butterscotch Marshmallow Sandwich Cookies Recipe

The image shows a group of round light brown cookie bases with a soft texture on a metal cooling rack placed on a white marbled surface. Each cookie base has one layer of thick light beige cream swirled on top in a circular motion, giving it a smooth and creamy look. The cookies are arranged in neat rows, with one plain cookie base without cream near the top right, and a large piping bag filled with the same light beige cream nearby. The whole scene feels clean and organized with a soft, creamy focus. photo taken with an iphone --ar 4:5 --v 7

Garnishes

For a whimsical touch, sprinkle a little crushed Biscoff cookie crumb on top or around the edges of your sandwiches. You could also drizzle a bit of melted butterscotch or chocolate for added visual appeal and flavor contrast. Fresh edible flowers or a pinch of sea salt can elevate the presentation to truly special.

Side Dishes

These cookies pair wonderfully with warm beverages like chai tea, coffee, or rich hot chocolate—each sip balances the sweetness and complements the buttery and marshmallow flavors. Serving them alongside a bowl of fresh berries or creamy vanilla ice cream can turn these treats into a delightful dessert experience.

Creative Ways to Present

Stack them in a rustic wooden box or wrap them individually in parchment paper tied with twine for charming party favors. Creating a dessert platter with varied heights by placing the Butterscotch Marshmallow Sandwich Cookies Recipe alongside small ramekins of butterscotch sauce invites guests to dip and double the indulgence. You can even slice them in half and sprinkle with toasted nuts for a crunchy contrast.

Make Ahead and Storage

Storing Leftovers

You can keep these sandwich cookies fresh at room temperature for up to 5 days if stored in an airtight container. The flavors actually deepen over time, making leftovers even more delightful. Just be sure to keep them away from direct sunlight or heat to maintain their texture.

Freezing

Both the baked cookies and the assembled sandwich cookies freeze beautifully for up to 3 months. Store the cookies and/or frosting separately in airtight containers or freezer bags to preserve freshness. When ready to enjoy, thaw overnight in the refrigerator before assembling or serving. You can also freeze unbaked cookie dough balls and bake fresh batches whenever the craving hits.

Reheating

If you prefer your cookies slightly warm, gently heat the assembled sandwich cookies in the microwave for about 10 seconds. This softens the frosting and brings out that comforting melted butterscotch flavor. Be careful not to overheat, or the marshmallow filling may become too runny.

FAQs

Can I substitute the Biscoff cookie butter with regular peanut butter?

While peanut butter will change the flavor profile, it’s not recommended as a one-to-one substitute here because Biscoff cookie butter offers unique spiced sweetness that defines this recipe. You could experiment, but expect a different outcome.

How can I make these cookies vegan?

To make a vegan version, substitute butter with a vegan alternative and use flax eggs instead of chicken eggs. For marshmallow fluff, look for a vegan brand or make your own, ensuring all ingredients fit your dietary needs. Note that texture and flavor might differ slightly.

Are these cookies gluten-free?

This recipe as is contains wheat flour and crushed Biscoff cookies, which contain gluten. To make a gluten-free version, use a gluten-free all-purpose flour blend and gluten-free crushed cookies. Make sure other ingredients like baking powder are gluten-free certified.

Can I make the cookie dough ahead of time?

Absolutely! The dough can be prepared and refrigerated for up to 2 days before baking. Just cover it tightly to prevent drying out. This makes it perfect for planning ahead for gatherings or busy days.

What’s the best way to pipe the butterscotch marshmallow frosting onto the cookies?

Use a piping bag fitted with a round tip for neat and even coverage. If you don’t have one, spreading with an offset spatula works wonderfully too. Leaving a small border around the edge helps prevent the frosting from oozing out when you press the cookies together.

Final Thoughts

Now that you know how to create these dreamy, flavor-packed treats, I encourage you to dive into this Butterscotch Marshmallow Sandwich Cookies Recipe—it’s truly a celebration of what homemade cookies can be. Whether you’re baking for a special occasion or just to bring a little joy to your day, these cookies deliver comfort, sweetness, and a touch of magic in every bite. Have fun making them your own, and watch how quickly they disappear once your loved ones get a taste!