Follow these simple steps to create your Christmas Crack:

1. Preheat Oven: Preheat your oven to 400°F (200°C).
2. Prepare Baking Sheet: Line a rimmed baking sheet with aluminum foil or parchment paper for easy cleanup.
3. Arrange Crackers: Place saltine crackers in a single layer on the prepared baking sheet. You may need to break some to fit.
4. Make Toffee Mixture: In a medium saucepan, melt the butter over medium heat. Add the brown sugar and stir until it comes to a boil. Allow it to boil for 3 minutes without stirring.
5. Pour Over Crackers: Pour the toffee mixture evenly over the crackers, ensuring all crackers are covered.
6. Bake: Place the baking sheet in the preheated oven and bake for 5-7 minutes, or until the toffee is bubbly.
7. Add Chocolate Chips: Remove from the oven and immediately sprinkle the chocolate chips over the toffee. Let it sit for a few minutes to melt.
8. Spread Chocolate: Once the chocolate chips are soft, use a spatula to spread the chocolate evenly over the toffee layer.
9. Add Nuts: If using, sprinkle chopped nuts over the melted chocolate and gently press them down.
10. Cool: Allow the Christmas Crack to cool at room temperature for about 30 minutes, or until set.
11. Break Into Pieces: Once cool, break the Christmas Crack into pieces and store in an airtight container.

These straightforward steps will guide you in creating this incredible holiday treat effortlessly.