Preheat oven to 350ºF

Prepare a 9-inch by 9-inch baking pan by greasing the pan with oil or butter and laying parchment paper.

Melt the butter and chocolate in a bowl.

Add in the sugar and mix until the sugar is dissolved, then mix in the vegetable/canola oil.

Add in 2 eggs, and mix until the mixture is light and fluffy, about 5-7 minutes with an electric hand mixer.

Sift in the dry ingredients - flour, cocoa powder, and salt. Mix just until incorporated.

Line the bottom of your baking pan with the graham cracker.

Pour the brownie batter on top, and spread evenly to the edges.

Bake for 22-28 minutes, until a toothpick poked into brownies, comes out clean.

Remove from oven, then sprinkle with graham crackers and chocolate chips.

Arrange the large marshmallows in one layer.

Return the pan back to the oven for 2-3 minutes, then increase the temperature to broil.

Broil the marshmallows until golden brown (watch carefully, so the marshmallows don’t burn; it takes about 2-3 minutes in my oven).

Remove and cool the brownies before cutting into them.

Cut the brownies into squares. The marshmallows can get messy. Use a sharp knife, run under hot water, wiping after every cut for clean brownie squares.