Toasted Marshmallow Sandwich Cookies

Ingredients:

• 25 marshmallows
• 1 and 3/4 cups premium flour
• 1 teaspoon baking powder
• 0.5 tsp salt
• 110 g unsalted butter, room temperature
• 0.5 cup granulated sugar
• 1 large egg
• 1 tsp vanilla extract
• 0.5 cups white decorative sugar
• 0.5 cups creamy marshmallows

Preparation:

1. Preheat oven to broil. Line a baking sheet with foil and lightly spray with cooking spray. Place the marshmallows on the baking sheet and broil until puffed and toasted (but not charred), turning once, 1 1/2 to 2 minutes. Set aside to cool.
2. Meanwhile, in a medium bowl, whisk together the flour, baking powder, and salt. In a large bowl, beat the butter and granulated sugar with a mixer on medium-high speed until light and fluffy, 3-5 minutes. Add the egg and vanilla extract and beat until smooth, about 1 minute, scraping down the sides of the bowl as needed.
3. Add the cooled toasted marshmallows and stir with a rubber spatula, breaking up the marshmallows until incorporated (it's okay if a few chunks remain). Add the flour mixture and knead the dough.
4. Cover the dough and refrigerate until firm and no longer sticky, 2-4 hours.
5. Position oven racks in the upper and lower thirds of the oven and preheat to 350°F (175°C). Line 2 baking sheets with parchment paper.
6. Place the decorative sugar in a shallow bowl. Form the chilled dough into 24 balls, about 1.5 tablespoons each. Roll the balls in sugar and place them on a baking sheet, about 2 inches apart.
7. Bake, rotating the baking sheets halfway through, until the cookies are set and lightly golden around the edges, 10-15 minutes. Let cool on the baking sheets for 3-5 minutes, then transfer to a wire rack to cool completely.
8. Turn half of the cookies over so they're flat-side up. Top with 2 teaspoons of marshmallow frosting. Let sit for about 5 minutes to allow the frosting to spread, then top with the remaining cookies, flat-side down. Press gently and let sit for about 10 more minutes; the frosting will spread to the edges.