01 -
Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
02 -
In a large bowl using an electric mixer, cream together the softened butter, peanut butter, granulated sugar, and brown sugar until light and fluffy, about 2-3 minutes.
03 -
Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract and mix until fully incorporated.
04 -
In a separate medium bowl, whisk together the flour, graham cracker crumbs, baking soda, and salt until well combined.
05 -
Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined. Be careful not to overmix.
06 -
Using a cookie scoop or spoon, form the dough into 1-inch balls (about 1 tablespoon each). Place them on the prepared baking sheets, spacing them about 2 inches apart. Gently press down on each ball with the palm of your hand or the bottom of a glass to slightly flatten.
07 -
Bake in the preheated oven for 10-12 minutes, or until the edges are golden but the centers still look slightly soft. Do not overbake as they will continue to firm up as they cool.
08 -
Allow the cookies to cool on the baking sheets for 5 minutes, then transfer to wire racks to cool completely.
09 -
While the cookies are cooling, prepare the filling. In a microwave-safe bowl, combine the chocolate chips and peanut butter. Microwave in 20-second intervals, stirring between each, until melted and smooth.
10 -
Allow the chocolate-peanut butter mixture to cool slightly (but not harden), then stir in the mini marshmallows. Let the mixture cool and thicken for about 5-10 minutes until it reaches a spreadable consistency.
11 -
Turn half of the cooled cookies upside down. Spread about 1-2 teaspoons of the marshmallow-chocolate filling onto each cookie bottom. Top with another cookie, right side up, pressing gently to create a sandwich.
12 -
Allow the sandwich cookies to set for about 30 minutes before serving. This helps the filling firm up slightly so it doesn't squish out when you bite into them.