Preheat oven to 350°F. Lightly grease an 8×8 baking pan or 8 inch cake pan.
In a medium bowl, whisk together flour, cocoa powder and baking powder (if using); set aside.
In a separate bowl, beat butter, eggs, syrup and vanilla. Add to dry ingredients and mix until just combined. Pour into prepared pan and bake for about 20 minutes or until just set. A toothpick inserted in the center will still have sticky-but-not-wet crumbs. Serve warm or at room temperature with fruit.