Combine 3/4 cup of sugar, flour and salt in a heavy sauce pan; whisk in egg yolks and milk. Cook over medium heat, whisking constantly, 5 to 7 minutes or until thickened. Remove from heat and stir in vanilla. Pour in a serving dish; cool. Cover and chill for 2 hours.
Beat whipping cream at medium speed with an electric mixer until foamy; gradually add 2 tablespoons of sugar, beating until soft peaks form.
Spread over custard in the serving dish. Top with fresh blackberries and garnish with mint springs if desired.
Yield: 4 servings with 15 minutes of preparation plus 7 minutes of cooking and 2 hours cooling time.