Preheat oven to 350.
Grease a 8x8-inch baking pan with cooking spray and set aside.
Sift together the flour and salt; set aside.
Place the butter and chopped chocolate in a saucepan and melt over low heat, stirring frequently, until melted and smooth.
Remove from heat and stir the sugar into the chocolate mixture; let cool for 3 minutes.
Pour the chocolate mixture into your mixer's bowl and beat in the eggs, one at a time.
Stir in the flour mixture with a wooden spoon.
Spread the batter evenly into the prepared pan.
Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.
Cool in pan on wire rack.
When cool, prick with a fork all over the surface and sprinkle with cherry liquer.