15 tablespoons butter
7 ounces chopped dark chocolate
1 cup sugar
4 eggs
rounded tablespoon flour

Heat oven to 350°F. Line an 8 inch round cake pan with parchment paper. Melt butter and chocolate together. Add sugar, stir with a wooden spoon and let cool a little. Add eggs one at a time, mixing well after each addition. Add flour and mix well. Pour into prepared pan and bake 30 minutes. Turn the oven off but leave cake inside for another ten minutes, then cool completely in pan on rack. Cover with plastic wrap, chill and take it out about an hour before serving.