Preheat oven to 350 degrees and line a 9 X 13 inch pan with parchment paper.
Add 2 1⁄3 cups of graham cracker crumbs in a bowl then stir in flour and salt until blended.
Put sugar, soft butter, and vanilla in a large mixing bowl. Beat until blended.
Add the flour, graham cracker crumbs, and salt mixture in with the butter mixture and mix until combined.
Take out 1 cup of this mixture. Set aside.
Spread the rest of the mixture in the baking pan. Press it evenly on the bottom of the pan.
Scatter the chocolate chips evenly on top of the crust.
Add spoonfuls of the marshmallow cream on top of the chocolate chips. Dip an offset spatula in hot water to heat before spreading the marshmallow cream over the chocolate chips. If needed, dip the spatula in hot water to remove any extra marshmallow cream.
Scatter the mini marshmallows on top.
Sprinkle 1 cup of the graham cracker mixture on top of the mini marshmallow.
Bake at 350 degrees until the mini marshmallow begins to turn to a light golden brown or 18-22 minutes.
Set aside to cool. Remove from the pan to cool completely before cutting into bars.