Gluten-Free Nanaimo Bars

Ingredients

• butter
• tablespoons white sugar
• tablespoons unsweetened cocoa powder
• gluten-free graham cracker crumbs
• egg
• shredded unsweetened coconut
• finely chopped walnuts
• teaspoon vanilla extract
• milk or non-dairy milk alternative
• custard powder
• sifted icing sugar
• ounces of semi-sweet chocolate
• tablespoons butter