1) Preheat oven to 190 degrees C.
2) Line a metal half sheet baking pan (30 by 45 cm) with baking 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.
3) Bake for 20 minutes or until golden brown. Serve hot or cold.