Nanaimo Bars

Ingredients:
Bottom Layer:
1/2 cup (1 stick) (113 grams) unsalted butter, room temperature
1/4 cup (50 grams) granulated white sugar
1/3 cup (30 grams) unsweetened cocoa (I use Dutch-processed)
1 large egg, beaten
1 teaspoon pure vanilla extract
2 cups (200 grams) graham cracker crumbs
1 cup (65 grams) coconut (either sweetened or unsweetened)
1/2 cup (50 grams) walnuts or pecans, coarsely chopped
Middle Layer:
1/4 cup (56 grams) unsalted butter, room temperature
2 - 3 tablespoons milk or cream
2 tablespoons vanilla custard powder (Bird's) or vanilla pudding powder
1/2 teaspoon pure vanilla extract
2 cups (230 grams) powdered sugar (confectioners or icing)
Top Layer:
4 ounces (115 grams) semisweet chocolate, chopped
1 tablespoon (14 grams) unsalted butter

Preparation:
Butter or spray a 9 x 9 inch (23 x 23 cm) pan with a non stick vegetable spray.
Bottom Layer: In a saucepan over low heat, melt the butter. Stir in the sugar and cocoa powder and then gradually whisk in the beaten egg. Cook, stirring constantly, until the mixture thickens (1 - 2 minutes). Remove from heat and stir in the vanilla extract, graham cracker crumbs, coconut, and chopped nuts. Press the mixture evenly onto the bottom of the prepared pan. Cover and refrigerate until firm (about an hour).
Middle Layer: In your electric mixer, or with a hand mixer, beat the butter until smooth and creamy. Add the remaining ingredients and beat until the mixture is smooth. If the mixture is too thick to spread, add a little more milk. Spread the filling over the bottom layer, cover, and refrigerate until firm (about 30 minutes).
Top Layer: In a heatproof bowl over a saucepan of simmering water, melt the chocolate and butter. Spread the melted chocolate evenly over the filling and refrigerate until the chocolate has set.
To Serve: To prevent the chocolate from cracking, using a sharp knife, bring the squares to room temperature before cutting.
Yield: Makes about 25 squares