Chocolate Marshmallow Cookies 

Chocolate Marshmallow Cookies 
Ingredients
2 cups all-purpose flour
¾ cup unsweetened cocoa powder
½ teaspoon baking soda
¼ teaspoon salt
1 cup (2 sticks) unsalted butter, room temperature
1½ cups granulated sugar
2 large eggs, room temperature
2 teaspoons vanilla extract
1 cup marshmallow fluff
Instructions
Combine dry ingredients
In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt until evenly blended. Set aside.

Cream butter and sugar
In a large mixing bowl, beat the room-temperature butter and granulated sugar with an electric mixer on medium speed until light and fluffy, approximately 3 to 4 minutes. Scrape down the sides of the bowl as needed.

Add eggs and vanilla
Add the eggs one at a time, mixing on low speed after each addition until fully incorporated. Stir in the vanilla extract.

Form the dough
Gradually add the dry ingredients to the wet mixture, mixing on low speed just until a cohesive dough forms. Avoid over-mixing to maintain a tender texture.

Chill the dough
Cover the bowl and refrigerate the dough for at least 1 hour. Chilling firms the dough, making it easier to handle and reducing spread during baking.

Preheat and prepare baking sheets
Position oven racks in the upper and lower thirds of the oven. Preheat to 350°F. Line two baking sheets with parchment paper or silicone baking mats.

Portion and shape
Using a cookie scoop or tablespoon, portion the chilled dough into balls approximately 1½ inches in diameter. Place them on the prepared baking sheets, spacing about 2 inches apart. Press a shallow indent into the center of each dough ball using your thumb or the back of a small spoon.

Add marshmallow swirl
Spoon approximately 1 teaspoon of marshmallow fluff into each indent. Using a toothpick or the tip of a knife, gently swirl the fluff into the surface of the dough, creating a marble pattern without fully incorporating it.

Bake
Bake for 10 to 12 minutes, rotating the baking sheets between the upper and lower racks halfway through. The cookies are done when the edges are set and the centers remain slightly soft.

Cool
Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely. This resting period allows the marshmallow to set slightly for easier handling.