source: Rebecca Rather's The Pastry Queen via Dinner and Dessert
½ cup (1 stick) unsalted butter
½ cup firmly packed dark brown sugar
1 tablespoon light corn syrup
2 cups old-fashioned rolled oats
1 teaspoon baking powder
¼ teaspoon salt
1/3 cup shredded coconut
½ cup bittersweet chocolate chips
Preheat the oven to 350 degrees. Grease an 8-inch square baking pan with butter or cooking spray. Melt the butter, brown sugar, and corn syrup in a saucepan set over medium heat. Stir 1 to 2 minutes, until the brown sugar is no longer grainy. Remove the pan from the heat. In a medium bowl, stir together the oats, baking powder, salt, and coconut. Add the butter mixture and stir to combine.
Spoon the dough into the pan. Lightly coat your fingers with cooking spray or butter and press the mixture evenly into the pan.
Bake for 20 to 25 minutes. Cool for 20 minutes and cut into narrow fingers. In a small, heavy saucepan, melt the chocolate chips over low heat, stirring constantly. Drizzle over the bars.