Preheat your oven to 375°F (190°C) and lightly spray a 9x13 inch baking dish with non-stick cooking spray.
Roll out one can of crescent rolls in the bottom of the baking dish, pressing any seams together to form an even layer.
Layer the deli-sliced roast beef evenly over the dough, followed by a sprinkling of Swiss cheese.
In a small bowl, mix the dry onion soup mix, melted butter, Worcestershire sauce, and garlic powder. Drizzle this mixture over the cheese layer.
Roll out the second can of crescent rolls and place it over the beef and cheese, pinching the seams together to create a smooth top layer.
Place the dish in the oven and bake for 15-20 minutes or until golden brown and fully cooked.
While your squares are baking, warm up one cup of beef broth in a small pot over medium heat.
Let your French Dip Squares cool slightly after baking before cutting them into squares.
Serve your freshly baked squares with warmed beef broth for dipping.