In a mixing bowl, combine butter and brown sugar. Mix on high speed for at least 3 minutes with an electric mixer to "cream" them together and begin dissolving the sugar.
1 cup salted butter, room temperature , 1½ cups light brown sugar, packed
Add in the egg and vanilla extract and mix for 1 minute, until the egg is fully mixed in and the mixture is fluffy.
1 large egg , 1 teaspoon vanilla extract
In a blender, pulse the graham crackers until they become a fine powder, or you can smash them in a gallon sized bag with a rolling pin, just be sure to make sure they get very well smashed into a fine powder like sand.
12 graham crackers (2 cups crumbs)
Add the graham cracker powder, flour, baking soda, and salt (cinnamon optional) to the cookie dough and mix on low speed until everything is mixed in, about 1 minute.
2 cups all purpose flour, 1 teaspoon baking soda, ½ teaspoon salt
Scoop the cookie dough onto prepared baking sheets with a large 3-4 Tablespoon cookie scoop. Smash the cookies slightly so they are about 2 inches.
Bake at 350 ℉ for 10-12 minutes, they will be starting to crack around the edges. Let cool completely before frosting.