Step 1

Make the cookies: In a medium bowl, whisk the flour, 1 cup of crushed graham crackers, cornstarch, cinnamon (if using), baking soda, baking powder, and salt. Set aside.

Step 2

In a large mixing bowl, beat the butter, granulated sugar, and brown sugar on medium speed until well blended. Reduce the speed to low and beat in the egg yolk and vanilla until smooth.

Step 3

Gradually add the dry ingredients to the wet, mixing gently by hand until just combined. Cover and chill the dough for an hour.

Step 4

Preheat the oven to 325°F and line 2 baking sheets with parchment paper or silicone baking mats.

Step 5

Portion the chilled dough into 2-tablespoon balls. Roll them in the remaining cracker crumbs and arrange them on prepared baking sheets, spacing each about 2 inches apart.

Step 6

Bake for 10-12 minutes, or until the edges are lightly golden. The centers may appear slightly underbaked but will firm up as they cool.

Step 7

Let the cookies cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.

Step 8

Make the frosting: In a clean mixing bowl, beat the softened butter on medium speed until smooth and creamy. Gradually add the powdered sugar, followed by the vanilla extract and salt. Add the marshmallow fluff and fold it in by hand.

Step 9

Spread the frosting over the cooled cookies and top with crushed graham crackers as a garnish, if desired. Enjoy!