If you follow any bloggers, surely you’ve stumbled upon Browned Butter Blondie blog creator Heather Mubarak’s delicious ideas. Now she has a book! Stuffed: The Sandwich Cookie Book (Chronicle Books 2023) is exactly what it sounds like: a celebration of everything you could possibly stuff between two cookies. A great example is this recipe! Here’s what the author has to say.

Thank you for reading this post, don't forget to subscribe!

These are really just fudgy brownies masquerading as cookies, and they’ve been breaking hearts and taking names since 2018. One of the very first recipes published on my blog, these uber-chocolatey numbers are perfect for those days when you can’t decide between a brownie and a cookie. Add a swirl of fluffy peanut butter frosting, and they are impossible to resist.

Makes 12 to 14 cookie sandwiches

Ingredients

Wannabe Brownie Cookies

• 1/2 cup plus 2 tablespoons [80 grams] all-purpose flour, spooned and leveled
• 2 tablespoons Dutch-process cocoa powder
• ¾ teaspoon baking powder
• ½ teaspoon salt
• 7 ounces [200 grams] good-quality semisweet chocolate, chopped
• 2 ounces [55 grams] bittersweet chocolate, chopped
• 6 tablespoons [85 grams] unsalted butter, at room temperature
• ½ cup [100 grams] granulated sugar
• ¼ cup [50 grams] light brown sugar, packed
• 2 eggs, at room temperature
• 2 tablespoons freshly brewed espresso or strong coffee, slightly cooled
• 1 ½ teaspoons vanilla extract
• 3 ounces [85 grams] mini semisweet chocolate chips
• Flaky sea salt, for sprinkling (optional)

Peanut Butter Frosting

• ½ cup [113 grams] unsalted butter, at room temperature
• 1 ½ cups [440 grams] creamy peanut butter, at room temperature (not all-natural peanut butter)
• 2 ¼ cups [270 grams] confectioners’ sugar, sifted
• 2 to 3 tablespoons heavy cream
• 2 teaspoons vanilla extract
• Pinch of salt (optional)

Instruction

Make the Cookies

1. Preheat the oven to 325°F [165°C]. Line two baking sheets with parchment paper or silicone baking mats.

2. In a medium bowl, sift together the flour, cocoa powder, baking powder, and salt. Whisk to combine and set aside

3. Create a double boiler by filling a medium saucepan with 2 to 3 inches [5 to 7.5 centimeters] of water. Bring the water to a simmer over medium-low heat. Place a heatproof bowl over the pan, making sure that the bottom of the bowl does not touch the water below. Add the semisweet chocolate, bittersweet chocolate, and butter and heat, stirring often. Do not overheat. Once melted, remove the bowl from the heat and stir until the mixture is smooth and shiny. Set aside to cool slightly.

4. In the bowl of a stand mixer fitted with the paddle attachment, cream together the granulated sugar, brown sugar, eggs, espresso, and vanilla until thickened, about 2 minutes. Add the chocolate mixture and blend on low speed until combined. Add the flour mixture gradually and mix until barely combined. You should still see some streaks of flour in the batter. The batter will be soft, similar to cake batter.

5. Remove the bowl from the mixer and gently fold in most of the chocolate chips, reserving 1 to 2 tablespoons for the tops of the cookies if desired. Do not overmix

6. Let the dough sit for 5 to 10 minutes at room temperature. Use a 2 tablespoon cookie scoop to portion the cookie dough onto the prepared baking sheets, leaving 2 in [5 cm] between each cookie

7. Bake for 8 to 10 minutes, or until the edges are barely set and the centers of the cookies still look soft and fudgy. The cookies will continue to bake a bit once removed from the oven. As soon as the cookies are out of the oven, use the inside arch of a fork to nudge the edges of the cookies in toward the center, working your way around each cookie while they are still hot. This will help make the cookies more uniform in size and shape for the sandwiches.

8. Allow the cookies to rest for 6 to 8 minutes on the baking sheets before using a spatula to carefully transfer them to a wire cooling rack. Let cool completely before assembling the sandwiches.

Make the Peanut Butter Frosting

9. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on medium speed until light and creamy. Stop the mixer and scrape down the sides of the bowl. Add the peanut butter and mix on medium speed for 1 minute.

10. Add the confectioners’ sugar, 1/2 cup [60 grams] at a time, while mixing on low speed. Once the sugar is incorporated, increase the speed to high and mix for 1 minute. Stop the mixer and scrape down the sides of the bowl.

11. Add 2 tablespoons of the heavy cream and the vanilla. Mix on medium-high speed until light and fluffy, 2 to 3 minutes. If the buttercream is too thick, add more heavy cream. Add salt, if using, and mix to combine.

12. Fill a piping bag with the frosting to use immediately or store tightly covered in the refrigerator for up to 2 weeks.

Assemble the Sandwich Cookies

13. Using an offset spatula, place a generous swirl of the Peanut Butter Frosting on the flat side of a cookie. Top with a second cookie, flat-side down, and gently press together. Repeat with the remaining cookies until all the sandwiches are assembled. If the frosting is soft, place the cookie sandwiches in the refrigerator for 20 minutes to set.

14. Store tightly covered in the refrigerator for up to 4 days. The Peanut Butter Frosting may soften too much if kept at room temperature.

Reprinted from Stuffed: The Sandwich Cookie Book by Heather Mubarak, with permission by Chronicle Books, 2023.