Preheat the oven to 400°F (205°C). Line a rimmed sheet pan with parchment paper or aluminum foil and arrange the saltines in into a single, flat layer that covers the entire sheet pan.

To a medium saucepan over medium heat, add the butter and brown sugar, stirring until the butter is melted.

Once the butter has fully melted, stir until well combined, then bring to a boil. 

Let it boil for 3 minutes without stirring, until the caramel forms thick, glossy bubbles, and the color deepens slightly. Remove from heat and immediately stir in the vanilla and salt (be careful – it will bubble up when you add the vanilla!).

Immediately pour the caramel mixture over the crackers and using an offset spatula, spread it into a thin, even layer that covers all of the crackers. 

Place the baking sheet in the oven and bake for 5 minutes, until the caramel is bubbling.

Remove from oven and immediately sprinkle white chocolate chips evenly over the caramel.

Let sit 2–3 minutes until melted, then spread into a smooth layer. You may need to return the baking sheet to the oven for 30 seconds or so to help the chocolate chips melt completely.

Sprinkle with desired toppings (freeze-dried strawberries, pistachios and chocolate eggs) while the chocolate is still melted.

Cool at room temperature for 15–20 minutes, then transfer to the fridge for 20–30 minutes until fully set.

Break into bite-sized pieces using your hands or a knife, and enjoy!