Preheat oven to 350 degrees Fahrenheit; line a 9x13 inch baking pan with parchment.

Beat butter, powdered sugar, and vanilla.

Gradually mix in flour until crumbly dough forms; fold in crushed pretzels.

Press evenly into prepared pan's bottom.

Bake 15 minutes, until edges are light brown.

Meanwhile, microwave caramels and cream in 30-second intervals until melted and smooth.

Drizzle caramel over warm shortbread; let set completely before cutting into bites.