Chewy Black + White Chip Oatmeal Sandwich Cookies.

I like sandwiches. And I like cookies.

However, would I like sandwiches in my cookies or cookies in my sandwiches? The latter… probably yes.

While most of my favorite sandwiches consist of some sort of crunchy bacon and toast and aioli and poached eggs, I wasn’t sure how well that would pair with a cookie. You know. You get it.

Hence the buttercream filling. Wait. The MARSHMALLOW buttercream filling.


Oh don’t get too excited. It’s just butter, marshmallow fluff (real or store bought works) and sugar. Fancy fancy. But not at all.

Guess what? It’s exactly one week until Christmas and I haven’t baked a thing yet. Well, besides these. Like they would even last a week. I have a list to get through people. I’m starting today.

That’s a lie. I’ll probably start on Saturday at midnight.

I’ll blast Mariah Carey, Barry Manilow, N*SYNC and maybe Lady Antebellum Christmas music. With a hint of Ariana Grande santa baby. I sort of have holiday iTunes ADD.

I’m copping out today like I do every now and then and using this chewy oatmeal chocolate chip recipe from a few years ago. I absolutely adore it and it’s one cookie I make constantly, regardless of how many new recipes need to come out of my kitchen. This time though, I swapped the baking powder for baking soda (accidentally on purpose, but not really. How does one go to the store every single day, sometimes multiple times per day, and still forget things?) resulting in a slightly thinner cookie but a chewy one nonetheless.

Ohmahgah. I can’t even stand the chewiness. It’s so ridiculously fabulous.

These cookies are thin and a bit crisp, but still packed with some chew. It’s like my dream is a little baked dough ball.

I’d like to faceplant into the center of these sandwiches and get stuck there for the next few days. Figuratively speaking, of course. I’m probably one of the only ones in the universe, but I LOVE this crazy time of year. I adore the hustle and bustle. I love going shopping or heck, just going to the mall and watching others shop. This season does not stress me out nor do I wish it away. I live for it. Crazy?

Maybe one day if I have some kids that will change, but I’m hoping not. It’s so fun. ‘Tis the season to wear glittery eye shadow, sparkles on your face and sequins on, well, everything. ‘Tis the season to stuff your face with cookies for breakfast and then go for a run.

Seriously the best time of year.

Did you make this recipe?

Chewy Black + White Chip Oatmeal Sandwich Cookies with Marshmallow Buttercream Filling


1/2 cup unsalted butter, at room temperature
1/2 cup sugar
1/2 cup loosely packed brown sugar
1 large egg
2 teaspoons vanilla extract
1 1/4 cup all-purpose flour
1/2 teaspoon baking soda
1/4 teaspoon salt
3/4 cups rolled oats
optional: 1-2 tablespoons milk, if dough is super crumbly
2/3 cup dark chocolate chips
2/3 cup white chocolate chips

marshmallow buttercream filling
1/2 cup unsalted butter, softened
1 cup marshmallow cream (homemade or store-bought is fine)
1/2 cup powdered sugar
1 teaspoon vanilla extract
1 pinch of salt


Preheat the oven to 375 degrees F.

Add the butter to the bowl of your electric mixer and beat until creamy. Add in the sugars and beat on high speed until fluffy, about 2 to 3 minutes. Add the egg and vanilla, mixing well until combined, about 2 minutes. Stir in the flour, baking soda and salt with the mixer on medium speed. Beat in oats until just combined. Add in 1 tablespoon milk if the dough appears too crumbly. Fold in the chocolate chips. Refrigerate the dough for 30 minutes.

Roll the dough in to equally sized 1-inch balls and place them on a nonstick baking sheet 2 inches apart. Bake for 9 to 11 minutes, until the edges are just golden. Wait until the cookies cool COMPLETELY before adding the buttercream in the center and sandwiching the cookies together.

marshmallow buttercream filling
Add the butter to the bowl of your electric mixer and beat until creamy. Add in the marshmallow and beat on medium speed until the mixture comes together, about 2 minutes. Add in the sugar, vanilla extract and salt, mixing on medium speed for another minute. Scrape down the sides of the bowl and mix the buttercream on high for 2 to 3 full minutes.

[cookies from my chewy oatmeal chip cookies]

All images and text ©.

Did you make this recipe?

Be sure to follow howsweeteats on instagram and tag #howsweeteats. You can also post a photo of your recipe to the howsweeteats facebook page.

I appreciate you so much!

A cookie cannonball into the center would be ideal.