Preheat your oven to 350°F, and line a 9x13 baking dish with parchment paper.
Mix together all the ingredients for the crumble in a bowl, until incorporated.
Press the crumble into the baking dish, and compress evenly. Bake for 10-12 minutes until lightly toasted.
In a bowl, cream together the butter with the custard powder until fluffy.
Sift in the icing sugar, and whisk until light.
Whisk in enough heavy cream to make a spreadable yet thick icing.
Spread the icing onto the crumble layer, spread until even. Chill for an hour before topping.
Melt the butter, and chocolate in the microwave.
Spread the chocolate over the top of the icing, and spread evenly. Chill the bars until firm about 4 hours.
Cut the bars into 35 squares.
Enjoy!
True Nanaimo Bars https://www.closethecooks.com/2020/02/22/the-true-nanaimo-bar/ February 22, 2020