Preheat your oven to 350°F (175°C).

Line a baking sheet with parchment paper and arrange the saltine crackers in a single layer.

In a medium saucepan over medium heat, melt the butter and brown sugar together, stirring constantly for 3-5 minutes until bubbling and golden-brown.

Remove the mixture from heat and whisk in the heavy cream and vanilla extract until smooth.

Pour the toffee mixture evenly over the arranged saltines, ensuring every cracker is coated.

Bake for about 10-12 minutes, until the toffee bubbles and turns golden around the edges.

Sprinkle cinnamon and powdered sugar over the warm toffee layer.

Allow to cool completely on the baking sheet, about 30 minutes, and then cut into bars or squares.