Description
Soft, chewy oatmeal cookies sandwiched with a homemade, stable marshmallow fluff filling. These nostalgic treats are easy to make, perfect for gifting, and capture the warm flavors of autumn.
Ingredients
Scale
- 1 cup (226g) unsalted butter, softened to room temperature
- 1 cup (200g) dark brown sugar, packed
- 1/2 cup (100g) granulated sugar
- 1 large egg, room temperature
- 1 teaspoon vanilla extract
- 2 cups (250g) all-purpose flour
- 2 cups (160g) old-fashioned rolled oats
- 1 teaspoon baking soda
- 1 teaspoon ground cinnamon
- 1/2 teaspoon salt
- 1 cup (200g) granulated sugar (for filling)
- 1/2 cup (170g) light corn syrup
- 1/4 cup (60ml) water
- 2 large egg whites, room temperature
- 1/4 teaspoon cream of tartar
- 1 teaspoon vanilla extract (for filling)
- Pinch of salt (for filling)
Instructions
- Make the marshmallow filling first: In a small saucepan, combine 1 cup sugar, 1/2 cup corn syrup, and 1/4 cup water. Heat over medium-high, stirring until sugar dissolves. Once boiling, stop stirring and attach a candy thermometer. Cook until 240°F (soft-ball stage), about 5-7 minutes.
- While syrup heats, beat egg whites and cream of tartar in a mixer until soft peaks form. Slowly pour the hot syrup in a thin stream into the beating egg whites. Beat on high speed until the bowl is cool to the touch and mixture is thick, glossy, and white (5-7 minutes). Stir in 1 teaspoon vanilla and a pinch of salt. Set aside to cool completely.
- Preheat oven to 350°F (175°C). Line two baking sheets with parchment paper.
- In a large bowl, beat softened butter, brown sugar, and granulated sugar until light and fluffy (about 3 minutes). Beat in the egg and 1 teaspoon vanilla.
- In a separate bowl, whisk together flour, baking soda, cinnamon, and salt. Gradually add dry ingredients to wet ingredients, mixing on low just until combined. Fold in rolled oats.
- Scoop dough onto prepared baking sheets, spacing cookies 2 inches apart. Bake for 10-12 minutes until edges are set and slightly golden but centers look soft.
- Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
- Once cool, spread a generous amount of marshmallow filling on the flat side of one cookie and sandwich with another. Optionally roll edges in granulated sugar.
- Store in an airtight container at room temperature for up to 5 days.
Notes
Ensure all ingredients are at room temperature for best results. Do not overmix the dough to maintain chewiness. The syrup temperature is critical for the marshmallow structure; use a thermometer. Cookies can be frozen as dough balls or assembled cookies.
- Prep Time: 30 minutes
- Cook Time: 12 minutes
- Category: Dessert
- Cuisine: American
Nutrition
- Serving Size: 1 cookie sandwich
- Calories: 220
- Sugar: 24
- Sodium: 120
- Fat: 8
- Saturated Fat: 5
- Carbohydrates: 38
- Fiber: 1
- Protein: 3
Keywords: oatmeal cream pies, brown sugar cookies, marshmallow filling, homemade marshmallow, fall dessert, comfort food, easy baking, nostalgic treats