1. Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Arrange graham crackers in a single layer on the prepared baking sheet, breaking them as needed to fit.
3. In a medium saucepan over medium heat, melt the butter and brown sugar together, stirring until the mixture comes to a boil. Let it boil for 2-3 minutes, then remove from heat.
4. Pour the hot butter-sugar mixture evenly over the graham crackers, spreading with a spatula to cover completely.
5. Bake in the preheated oven for 5 minutes, or until the sugar mixture is bubbly.
6. Remove from the oven and immediately sprinkle chocolate chips over the top. Let them sit for a minute to melt, then spread the melted chocolate evenly with a spatula.
7. Scatter mini marshmallows over the chocolate layer, and sprinkle with sea salt and optional nuts.
8. Return to the oven for an additional 2-3 minutes, until the marshmallows are slightly toasted.
9. Let the S’mores Crack cool completely in the pan, then break into pieces and enjoy!

Here’s a little tip from my kitchen: To speed up the cooling process, pop the baking sheet in the fridge. This will help set the chocolate and make breaking the crack into pieces much easier.