Preheat oven to 375° F. Line 2 baking sheets with aluminum foil. Lightly butter and flour. Trace six 3-inch circles on each, leaving at least 2 inches between circles. Combine Silver Palate Thick and Rough Oatmeal, brown sugar, flour, baking powder and salt in a food processor and process for 1 minute. Add butter and egg and process until blended. Spoon a rounded tablespoonful of batter in each circle. Spread as neatly as possible with a metal spatula to a thickness of about 1/8 inch. Bake until lightly browned, 9 to 10 minutes. Remove and transfer cookies on foil to a rack to cool completely. Remove foil, spread about 1 tablespoon Silver Palate Raspberry Fudge Sauce on half of the cookies. Cover with remaining 6 cookies, gently pressing together. Dust with confectioners' sugar, if desired.