Firmly packed brown sugar
Preheat oven to 350 F. Beat butter, sugars, egg and vanilla together in bowl until creamy. In a seperate bowl, combine flour, soda, baking powder, and salt; stir into sugar mixture and mix well. Stir in coconut and cornflakes. Drop dough by teaspoons about 2 inches apart onto ungreased cookie sheets. Bake for 8 to 10 minutes, until lightly browned. Cool slightly, then remove from pan onto racks to finish cooling.
Source: Creative Cooking: Desserts : by Marian Hoffman
From the collection of K. Deck