Preheat oven to 350 degrees.

Line a baking sheet with parchment paper (or aluminum foil) and lightly spray with non-stick cooking spray.

Spread the crackers in an even layer on the baking sheet.

In a large pan on medium heat, melt the butter. Add the brown sugar and vanilla. Stir until the brown sugar is dissolved.

Turn up the heat until the mixture begins to boil. Stir continuously for about 3-4 minutes while the mixture gets bubbly and lighter in color.

Turn off the heat and quickly pour the mixture over the top of the crackers. Mix gently with a rubber spatula until all of the crackers are completely coated.

Sprinkle the kosher salt over the top of the crackers.

Bake for 8-10 minutes, monitoring closely to prevent burning.

Allow the crackers to cool, then break into pieces. Serve immediately or store in an airtight container.