Roughly chop the chocolate and pour it into a medium-sized bowl. In a microwave-safe measuring cup, heat cream in the microwave for 20-30 seconds until it just begins to bubble.
Then, pour the warm cream over the chocolate and let sit for 1-2 minutes until it begins to melt. Mix them together until combine. If your chocolate does not completely melt after pouring in the warm cream, you can place it in the microwave at 5-second intervals until it is completely melted.
Place the ganache in the fridge and let chill for at least an hour. Then, spoon out 1/2 teaspoons on the ganache and roll in your hands to form a ball.
Place the ball on a parchment-lined pan. Once you have scooped all of the ganache places the balls into the freezer and chill for at least 1 hour.
In a small bowl, mix together graham cracker crumbs, sugar and melted butter. Then, spoon a teaspoon of the mixture into the bottom of a lightly greased mini muffin pan. Press the crust firmly and then set aside.
Preheat the oven to 350 degrees F. In a small saucepan over low heat, melt the butter and sugar together until the butter is completely melted and the sugar begins to dissolve about 2 minutes. (do not boil)
Remove from the heat and sit to cool slightly. Meanwhile, in a medium bowl stir together cocoa, flour, baking powder, espresso powder and salt. Once the butter mixture has cooled, mix in the vanilla and egg until just combined. Then add the mixture to the dry ingredients.
Pour batter a small amount of batter onto the prepared crust. Then, place the frozen middle on top. Spoon remaining batter on top making sure the chocolate middle is completely covered. Place int he oven and bake for 10-12 minutes. There may be a slight depression in the middle of your brownie and that's okay.
Pipe a large dollop of the marshmallow fluff onto each brownie, after they’ve cooled down. Roast quickly with a brûlée torch, topped with graham cracker crumbs and chocolate shavings.