Combine the graham cracker crumbs and melted butter then mix until well combined. Firmly press the graham cracker mixture an 8×8 inch pan then bake for 5 minutes.
Melt the butter in a small pot over low heat. While still on heat, add both sugars. Once they’re dissolved, whisk in cocoa powder. Remove from heat and set aside.
In a small bowl whisk the egg, vanilla extract and salt. Whisk the sugar mixture into the egg mixture until very smooth. Fold in flour until just combined.