Flourless Peanut Butter Cookies

What makes the famous 4-ingredient peanut butter cookies from Ovenly even more decadent? Filling them with whipped vanilla buttercream! The originals garnered a cult following, with variations made by the likes of Smitten Kitchen and Alton Brown, but I’ve taken the chewy and insanely addictive recipe to a new level with these Flourless Peanut Butter Cookies with buttercream filling.

Okay, honestly? These cookies are PERFECT just the way they are. Not only are they super easy to put together, they only have 3 (4 or 5 if you’re feeling fancy) ingredients that are naturally gluten-free. When I found out that you could make these without any butter or flour and still have a chewy, flavorful cookie my mind was totally blown. And while we are being honest, the texture is better than any of the cross-hatched, peanut butter cookies I’ve ever had.

I wanted to jump on the bandwagon and test them out myself. My husband accidentally ordered a pandemic-sized jar of peanut butter off Amazon that were destined for cookies. Coupled with my kids’ pleads to be in the kitchen every day, I knew this would be the perfect recipe for us.

But how do you elevate something that is already so simple and so perfect? Just add frosting.

Whipping softened butter, confectioners’ sugar, and heavy cream spiked with vanilla bean paste creates the lightest, fluffiest frosting. American buttercream can be overly sweet and heavy, but if whipped to perfection, it is creamy and airy at the same time.

The key to whipped frosting is room temperature butter, heavy cream, and time. You might think heavy cream would weigh things down more than milk, but given the proper mixing time, it fluffs up the buttercream. The ingredients will come together rather quickly, but don’t stop there! Continue to mix for at least a few minutes. The peanut butter cookies are pretty decadent on their own, so it’s important that we lighten up the filling so the cookies aren’t too heavy.

If you do not have heavy cream for the filling, use regular milk but decrease the amount to 2 tablespoons. It will not whip up as light and fluffy but should still be creamy and delicious. Whatever the case, these flourless peanut butter cookie sandwiches are some seriously indulgent treats.

To chill or not to chill? Several variations around the web say to chill the cookie dough before scooping. In my own kitchen, I did not find this necessary. Perhaps my eggs still had some chill to them or my kitchen is cooler in general, but those baked right after the batter was prepared versus those that had been chilled had no noticeable differences.

The original cookies have a signature look that’s attributed to the scoop that is used to portion them. The dough should be firm enough to hold the shape of the cookie dough once scoop and released from a mechanical cookie or ice cream scooper. If it fails to hold its shape, then refrigerate the dough for at least 30 minutes before trying again.

Since my cookies were destined for sandwiches, I wanted mine to bake up slightly flatter. Gently pressing down on the cookie dough balls before baking helped achieve the look and shape I wanted.

Flourless Peanut Butter Cookies

adapted from Ovenly
makes about 9 cookie sandwiches

4-ingredient Peanut Butter Cookies

1 ¾ cups (335 g) packed brown sugar
2 large eggs
½ teaspoon vanilla bean paste
1 ¾ cup (450 g) smooth peanut butter
flaky salt, for sprinkling

Pre-heat the oven to 350°F. Line a baking sheet with parchment and set aside.

In a large mixing bowl, whisk together the brown sugar and eggs until smooth. Add the vanilla bean paste and mix until combined

Add the peanut butter and stir together until completely smooth.

Using a 2-tablespoon mechanical scooper/disher, scoop the dough into balls and place on the lined baking pans, at least two inches apart.

Bake the cookies for 18 to 22 minutes. When done, then should be set around the edges and slightly cracked on top. Sprinkle with flaky salt while they are still warm. Allow cookies to cool on a wire rack before filling.

*If dough is reluctant to hold its shape, freeze dough for about 15 minutes or place in the refrigerator for 30 to 60 minutes.

Whipped Vanilla Filling

½ cup unsalted butter, at room temperature
2 cups confectioner’s sugar
¼ cup heavy cream
½ teaspoon vanilla bean paste

In the bowl of a stand mixer fitter with the paddle attachment, beat the butter until smooth - about 2 minutes.

With mixer at low speed, gradually add the confectioners’ sugar, vanilla bean paste, and heavy cream, scraping bowl occasionally. Mix until blended.

Continue to beat at medium-high speed 3 to 5 minutes, until buttercream is light and airy and nearly white.

To Assemble

Pipe on or spread a thin layer of filling on the bottoms of half of the cooled cookies. Top the filling with the remaining cookies to create sandwiches.

Baker’s Notes

• I used dark brown sugar but light brown or a combination of the two should be fine.

• Substitute pure vanilla extract for vanilla bean paste if that is all that is available you.

• If you do not have heavy cream for the filling, use regular milk but decrease the amount to 2 tablespoons. It will not whip up as light and fluffy but should still be creamy and delicious.

• Several variations of this recipe around the web call for the dough to be chilled before scooping. I did not find this necessary in my own kitchen, with both versions baking up very similarly. If your cookie dough is too soft after mixing and doesn’t hold its shape, then chill in the refrigerator for at least 1 hour.

• Use smooth peanut butter - like Skippy or Jif. Not the natural stuff or anything that needs to be vigorously stirred.

• Leftover cookie sandwiches may be frozen. Wrap well in plastic. Eat directly from the freezer or allow to soften.