Preheat the oven to 400°F. Line a 10x15-inch jelly roll pan with nonstick aluminum foil or regular heavy-duty foil, covering the bottom and sides. Place the saltine crackers in a single layer on the bottom.

Place the brown sugar, butter, and salt in a medium-sized saucepan. Cook on medium heat, stirring frequently, until the butter melts. Continue to cook for another 3 to 5 minutes, until the mixture comes to a boil and emulsifies into a smooth sauce. Remove from heat and stir in the vanilla extract.

Pour the hot brown sugar mixture over the saltine crackers, spreading to evenly coat them.

Bake in the oven for 5 minutes until the caramel is hot and bubbly.

Melt the chocolate in a microwave-safe bowl in 30-second intervals, stirring each time, until fully melted.

Once the crackers are done baking, let them cool for 1 minute, then pour the melted chocolate over the crackers and spread evenly with a spatula.

Let the crackers cool to room temperature, then refrigerate to chill overnight.

Remove the cooled candy from the pan and gently peel away the foil. Cut the candy into snack-sized pieces using a chef's knife.