Preheat the oven to 350 degrees F. Lightly grease a 13 by 9-inch baking pan.
In a large bowl, mix together the brown sugar, flour, and butter. Add eggs and vanilla and stir well. Fold in coconut, pecans, and chocolate chips until well combined. Spread the batter evenly in the prepared pan and bake for 30 to 35 minutes, or until a toothpick inserted through the middle comes out clean. Cool the cake completely in the pan before cutting it into squares.