- 1/3 cup unsalted butter, cut into pieces
- Preheat oven to 350 F. Butter and line a 9-inch square baking pan with parchment.
- Over a pot of simmering water start to melt butter. Add white chocolate and stir until melted. Allow to cool to room temperature.
- In a mixer fitted with the whisk attachment, whip eggs until creamy. Add sugar and vanilla and continue to whip until pale and thick. Reduce speed to medium and add cooled, melted white chocolate.
- In a separate bowl, sift together flour, baking powder and salt and stir into egg mixture, by hand. Stir in pecan pieces and spoon into prepared pan. Bake 45 minutes.
- When cooled make peanut butter icing: put 1 tablespoon soft butter, ½ teaspoon vanilla, ¼ cup peanut butter and 1/8 cup skim milk in mixing bowl and cream together. Add 1 cup confectioner's sugar and mix until thick and creamy. Ice Brownies and chill.
- When chilled melt 150g white chocolate with 1 tablespoon butter and 100 g unsweetened chocolate with 1 teaspoon butter (separately!). Cover chilled peanut butter icing with layer of white chocolate and chill, then cover white chocolate with melted unsweetened chocolate. Chill. Cut and serve when top layer of chocolate has hardened.