BROWN BUTTER: In a skillet, brown the butter over medium-low heat. The butter will melt, then after a few minutes, will start to bubble, followed by seeing the parts of the butter separate into clear yellow and white parts. After another few minutes, the white specks will turn brown. At this point, take the pan off the heat. Don’t keep the pan on the heat long after the specks become brown, or your butter will burn. Let the butter sit till it cools and solidifies again. To speed up this process, you can pour the butter into a dish and set it in the fridge, stirring every 5 minutes till it’s a soft and creamy consistency.
COMBINE WET INGREDIENTS: Add the soft butter and peanut butter to the bowl of a stand mixer fitted with a paddle attachment and mix for a few minutes until smooth and fluffy. Add the brown sugar and white sugar and beat again until creamed. Add the eggs and vanilla and mix again.
BREAK UP GRAHAM CRACKERS INTO PIECES: Place the graham crackers in a zipper-top bag and break them into pieces by breaking them up by hand or using a rolling pin. (You don’t want the crackers to be all small crumbs but quite a few pieces about pea size.)
MIX DRY INGREDIENTS & ADD TO WET INGREDIENTS: In a medium mixing bowl, whisk together the flour, baking soda, and salt. Add this mixture and the graham cracker pieces to wet ingredients in the mixer and stir until just combined.
STIR IN S'MORES ADD-INS: Add the Reese’s Minis and marshmallows and mix gently by hand until just combined. Some of the Reese’s Minis will break, but be gentle and do not smash all of them.
CHILL COOKIE DOUGH: Cover the bowl with plastic wrap and refrigerate for 30 minutes while your oven preheats to 350℉.
SCOOP DOUGH ONTO PANS & BAKE: Line 2 baking sheets with parchment paper or silicone mats, and spoon 3 tablespoon-sized dough balls (about 50 g each) on the baking sheet several inches apart. Do not overcrowd your baking sheet, or you will have cookies that stick together.Bake for about 10-12 minutes until any marshmallows on top have melted and started to turn light brown and the edges of the cookies look set.
COOL COOKIES: Remove pan from oven and let cookie cook on the baking sheet for 8-10 minutes before removing to a wire cooling rack to finish cooling.
Peanut butter Chocolate drizzle, if using;
Melt the chocolate chips and peanut butter together in 20-30-second increments at 50% power, stirring in between each time in the microwave. Only microwave until smooth. If it gets too stiff to drizzle at some point while decorating the cookies, microwave for another 15-20 seconds.
Buttered graham cracker topping, if using;
Using the same zipper bag you previously used to crush graham crackers, crush 4 graham crackers squares (2 full sheets) into fine crumbs. Pour the crumbs and 1 ½ tablespoons melted butter into a small bowl. Using a fork, mix them to create a sandy consistency.
Assemble
Once the cookies have cooled, drizzle the chocolate on top using a fork or a sandwich-size zipper bag with a very small end cut off. Sprinkle the graham cracker topping on top.