7 Tablespoons unsalted butter
4 ounces plus 4 ounces white chocolate, finely chopped
2 large eggs
⅛ teaspoon salt
½ cup sugar
1½ teaspoons vanilla extract
1 cup all-purpose flour
4 ounces bittersweet chocolate, finely chopped
½ cup heavy whipping cream
3 Tablespoons unsalted butter, cut into pieces
⅓ cup sugar
⅓ cup dark brown sugar, firmly packed
⅛ teaspoon salt
½ cup sifted unsweetened cocoa
¼ cup strong brewed coffee
Preheat oven to 350 degrees. Line an 8-inch square pan with foil. Lightly grease foil.
Melt butter over low heat in a small saucepan. Remove butter from heat and add 4 ounces white chocolate. Do not stir. Beat eggs and salt at high speed until frothy, about 30 seconds. Continue to beat eggs, about 2 to 3 minutes, while gradually adding sugar. Add butter mixture and vanilla. Blend well. Slowly add flour. Beat quickly until smooth. Fold in remaining 4 ounces white chocolate and bittersweet chocolate. Pour batter into prepared pan and bake 35 minutes. Allow to cool in pan on a wire rack.
Chocolate Sauce: Combine cream and butter in a small saucepan. Cook over moderate heat, stirring constantly, until butter melts and cream begins to boil. Add sugars and stir until dissolved. Reduce heat. Add salt and cocoa. Whisk until smooth. Remove from heat. Thin with coffee if desired. Serve warm or at room temperature.
Coat bottom of a dessert plate with chocolate sauce. Place a brownie in center of plate and top with a scoop of vanilla ice cream. Garnish with fresh mint and fresh berries. Makes 1 to 1½ dozen brownies.