Preheat oven to 375 degrees F.
Line a metal half sheet baking pan (12 by 17-inches) with parchment paper and butter. In large bowl, mix together butter, cheese, flour, garlic salt and cayenne. Turn out onto floured surface; knead lightly to blend well. Spread evenly into prepared pan. Score, with a paring knife, into small squares or rectangles. Prick each square with a fork twice to make a cross shape. Bake for 20 minutes or until golden brown. Serve hot or cold.