Into a bowl, sift together the flour, salt, and cayenne. Blend in the butter and Cheddar cheese. Stir in the cream, stirring until the mixture forms dough. Chill, wrapped in wax paper, for 2 hours. Roll out dough 1/16-inch thick on a lightly floured surface and cut into rounds, using a 1-1/2-inch cutter. Reroll scraps and cut out more rounds. Arrange on baking sheets, brush them lighly with the egg, and bake in the middle of a preheated 450f oven for 5-7 minutes, or until browned lightly. In a small container, cream together the Swiss cheese and softened butter. Arrange half the rounds, bottom sides up, on baking sheets. Divide the cheese mixture among them. Make sandwiches by pressing the remaining rounds on top and pressing lightly. Bake the croutes in the 450f oven for 4 minutes, or until the cheese is just melted.
Makes 46 croutes.
A Gourmet 1969 favorite.