Preheat your oven to 350 degrees
Make the graham cracker crust by combining 1 1/4 cups of finely crushed graham crackers with 3 tablespoons of granulated sugar and 5 tablespoons of melted butter and set aside
Make the chocolate cookie layer by whisking 1/2 cup of melted butter, 2 tablespoons of vegetable oil and 1 cup of granulated sugar until combined. Add 1 large egg and 1 teaspoon of vanilla extract and whisk until creamy. Add 1/3 cup of natural unsweetened cocoa powder, 1 1/4 cups of all purpose flour, 1/2 teaspoon of baking powder and 1/4 teaspoon of salt and mix until just combined
Spray a mini cupcake tin with non stick spray or line with mini cupcake liners
Add 1 teaspoon of the graham cracker mixture into each space and press down firmly
Add 1 rounded teaspoon of the chocolate cookie batter and gently press with a damp finger
Bake the cookies for 6-7 minutes in a 350 degree oven
As soon as you pull the cookies out of the oven, gently press mini marshmallows into the tops of each warm cookie
Allow the cookies to cool for several minutes before transferring them out of the cupcake tin
Brûlée the marshmallows (optional)
Store left overs in an airtight container at room temperature