Preheat oven to 180 celsius and prepare a baking pan by lining it with a sheet of parchment paper, leaving a few inches of overhang on the sides to allow for easy removal. Set aside.
Pour the batter into your prepared baking pan, using a spatula to distribute it evenly. Bake for 35 mins or until a toothpick comes out clean. Let cool completely. Let it cool.
Melt dark chocolate in microwave. Heat it on medium high for about 30 seconds to start with. Remove from the microwave and stir. Repeat heating at shorter intervals, 15 to 20 seconds, stirring in between, add maple syrup and stir until the chocolate is completely melted and has a smooth consistency.