Preheat the oven to 350 degrees. Grease a 9x13-inch baking dish with non-stick cooking spray and line with parchment paper. Set aside. In a medium bowl, combine the flour, cocoa powder, Morocco spice and salt. In a large microwave-safe bowl, combine the butter and 2 ounces of the chopped chocolate. Melt in 20 second intervals, stirring between each, until fully melted and smooth, about 1 minute total. Whisk in the sugars until well combined. Add the eggs and vanilla and whisk until smooth. Add in the dry ingredients and remaining chopped chocolate. Using a rubber spatula, gently fold everything together until smooth (being careful not to over mix). Spread batter evenly into prepared baking dish and top with a pinch of flaky salt. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven and place over a write rack. Cool completely before slicing and serving.