- 1 stick unsalted butter
- 1/2 cup packed light brown sugar
- 1/4 teaspoon salt
- 3/4 cup sweetened flaked coconut
- 3/4 cup rolled oats
- 1/4 cup all-purpose flour
- 3 ounces fine-quality bittersweet chocolate, finely chopped and melted
- 3 ounces fine-quality white chocolate, finely chopped and melted
- Equipment: 2 (17-by 11-inch) nonstick bakeware liners such as Silpats; 2 heavy-duty sealable bags
- Preheat oven to 350°F with rack in middle. Line 2 large baking sheets with nonstick liners.
- Melt butter with brown sugar and salt in a metal bowl set over a pot of simmering water, stirring occasionally. Stir in coconut, oats, and flour until just combined. Remove pot from heat but keep batter warm over pot (so batter is easier to spread).
- Drop rounded teaspoons of batter at least 3 1/2 inches apart on 1 baking sheet and spread each to about 2 inches with an offset spatula or back of a spoon. Bake until cookies are bubbling and golden brown, 8 to 12 minutes. Cool on baking sheet on a rack until firm, 3 to 4 minutes, then transfer cookies to rack to cool completely. Form and bake more cookies on second baking sheet (wipe liners clean and cool between batches).
- Cool melted chocolates slightly. Transfer each to a sealable bag and snip a 1/16-inch opening at a corner of each bag. Put some of cooled cookies on a parchment-lined tray that will fit in freezer, then pipe chocolates decoratively over cookies. Freeze 2 to 3 minutes to set chocolate, then carefully remove cookies from parchment.