Nanaimo Bars

When I was little,  my parents' friends would exchange baked goods on Christmas Eve. We all loved the Dutch butter cake we used to get with almonds on top, but each of us had favourites from the plate of mixed cookies that another colleague's wife made.  Two in particular we have tried to recreate for our grown-up Christmasses -- butter tarts and nanaimo bars - both Canadian classics.

Here's our favourite version of Nanaimo bars - based on a recipe in Annie Bell's Baking Bible.

INGREDIENTS

Biscuit Base
150g/5.3oz/ 2/3 cup softened unsalted melted butter
100g/3.5oz digestive biscuits  broken into pieces  or 1 1/4 cups graham cracker crumbs
60g/2oz walnut pieces (a generous half cup)
40g/1.4oz / 1/3 cup good quality cocoa powder, sifted
100g/3.5oz / 1/2 cupgolden caster sugar
80g/2.8oz / 7/8 cup desiccated unsweetened coconut
2 large eggs, beaten

Custard Cream
100g/3.5oz/ 1/2 cup  softened unsalted butter
2 tbsp custard powder (or a little more if you like them extra custardy as advocated here)
½ tsp vanilla extract
250g/8.8oz / 2 cups icing/confectioners sugar
2 tbsp milk  (or Tia Maria/Kahlua for a flavoured version)

Chocolate topping

150g/5.3oz dark chocolate at least 70%

25g/1oz 2 tablespoons unsalted butter

4 Tablespoons black coffee or coffee liqueur (tia maria or kahlua)

To assemble: 

Preheat the oven to 180°C (356°F). Butter or line a 23cm square x 4cm deep cake tin or brownie tin (or equivalent traybake tin, for example, 25cm x 20cm).

Whiz the digestives and the walnuts to crumbs in a food processor. Add the cocoa and sugar and whiz again, then transfer the mixture to a large bowl.

Mix in the coconut. Stir in the melted butter, then add the beaten eggs, stirring until combined. Bake in the pre-heated oven for 15 minutes, then remove from the oven and leave to cool. Don't overbake!

For the filling, beat the butter in a large bowl for about a minute until pale and fluffy.  Mix in the custard powder and the vanilla, and then the icing sugar.  Mix in the milk or kahlua in until smooth and creamy, like a stiff buttercream frosting.  Spread on the cooled base, and chill. 

For the top layer, break up the chocolate and gently melt it with the butter  and coffee or liqueur in a double boiler or in a bowl set over a pan containing a little simmering water.   If the chocolate separates, beat briskly with a tablespoon or two of cold water until it comes together again.  

Remove from heat and leave to chill slightly, then smooth the chocolate mixture over the custard cream. 

Chill, cut into small pieces and serve.