Plate 06 of 10

Nanaimo Bars

The unbaked three-layer bar from Vancouver Island. A tempered-egg base of graham crumbs, coconut, walnuts and cocoa, a pastel yellow buttercream made with English custard powder, and a dark chocolate top that snaps cleanly under a warm knife.

Prep: 35 min
Cook: 2 hr
Serves: 16 squares, from a 20 cm pan
Difficulty: Medium

Researched · Kitchen testing pending

Neatly cut squares showing three sharp layers: a dark crumbly base, a thick pale yellow custard cream, and a glossy dark chocolate top.

On the eastern shore of Vancouver Island, in the harbour city of Nanaimo, miners’ wives and church guilds sent dessert-bar recipes to community cookbooks in the 1950s, and one of them became a national staple. It needs no oven; it is built by setting three layers at staged temperatures.

The base is a dark, chewy, crunchy press of graham crumbs, coconut, walnuts and cocoa bound with a tempered egg. The middle is a rich pastel-yellow buttercream made with English custard powder, which gives the colour and the vanilla-starch flavour. The top is dark chocolate melted with a little butter so it snaps cleanly under a warm knife.

Ingredients

Base
115 gUnsalted butter, melted
50 gGranulated sugar
30 gDutch-process cocoa powder, sifted
1 largeEgg, lightly beaten
180 gGraham cracker crumbsor digestive biscuit crumbs
80 gShredded desiccated coconut
60 gWalnuts or pecans, finely chopped
Custard layer
115 gUnsalted butter, softened
45 mlHeavy cream
30 gBird's Custard Powderthe English cornflour custard powder, and not optional
250 gIcing sugar, sifted
Chocolate top
150 gSemi-sweet dark chocolate, about 60 percent, finely chopped
30 gUnsalted butter

The tempered base

Cooking the egg with the butter, sugar and cocoa over a water bath to 71 °C thickens it into a custard that binds the crumbs, coconut and nuts into a solid, chewy layer without an oven.

Why custard powder

Bird's is cornflour, salt, vanilla and annatto colour. Beaten into butter and icing sugar it makes a stable emulsion, and the starch absorbs the cream so the buttercream neither turns grainy nor melts at room temperature. Instant pudding mix makes a runny, sweet paste instead.

Butter in the chocolate

A little butterfat lowers the melting point of the cocoa butter, so the top slices cleanly instead of shattering into shards and tearing the custard beneath.

The five tastes on this plate

Salt is a pinch in the base against the sweet cream. Fat is butter in all three layers, cream in the middle and cocoa butter on top. Acid is the bitter edge of the dark chocolate. Heat is absent. Umami is toasted walnut, Dutch cocoa and dairy.

Equipment

20 cm square metal baking pan lined with parchment, with overhang
Heatproof bowl over a saucepan, for the bain-marie
Stand mixer with a paddle, or a hand mixer
Offset spatula
Thin sharp knife and a jug of hot water

Metal pans chill fast and release cleanly. Leave parchment tabs over the sides so the whole slab lifts out for cutting.

Method

Cook and press the base30 min
Set a heatproof bowl over simmering water. Melt the butter, sugar and cocoa, whisking smooth. Slowly whisk in the beaten egg and cook 2 minutes, whisking constantly, until it thickens to a custard at 71 °C. Off the heat, stir in the crumbs, coconut and nuts to a dense dark dough. Press firmly and evenly into the lined pan with the base of a flat measuring cup. Chill 20 minutes.
Over simmering water, melt butter, sugar and cocoa until smooth. Slowly whisk in egg; cook, whisking constantly, 2 minutes to thick custard at 71 °C. Off heat, mix crumbs, coconut and nuts. Press evenly into lined pan with a flat cup; chill 20 minutes.
Beat the custard layer40 min
Beat the softened butter on medium-high for 3 minutes until pale and fluffy. Add the cream, custard powder and icing sugar, mix on low to combine, then beat on medium-high 3 minutes until light, smooth and pastel yellow. Spread evenly over the chilled base with an offset spatula. Chill 30 minutes until firm.
Beat softened butter medium-high 3 minutes until pale and fluffy. Mix cream, Bird’s custard powder and icing sugar in on low; beat medium-high 3 minutes until smooth and light yellow. Spread over cold base; chill 30 minutes until firm.
Melt the chocolate5 min
Melt the chopped chocolate with the butter over simmering water, or in 20-second bursts in the microwave, stirring until smooth and glossy. Let it cool to lukewarm, about 40 °C. Hot chocolate on cold custard melts the custard.
Melt the chopped chocolate with the butter over simmering water, or in 20-second bursts in the microwave, stirring until smooth and glossy. Let it cool to lukewarm, about 40 °C. Hot chocolate on cold custard melts the custard.
Pour and chill30 min
Pour the lukewarm chocolate over the custard and tilt the pan to spread it into a level sheet. Refrigerate 30 minutes until just set but not rock hard.
Pour the lukewarm chocolate over the custard and tilt the pan to spread it into a level sheet. Refrigerate 30 minutes until just set but not rock hard.
Cut cleanly10 min
Dip a thin sharp knife in hot water and wipe it dry. Score a four-by-four grid, then press the warm knife straight down through all three layers in one motion, wiping and reheating between cuts. Lift out with the parchment tabs. Serve chilled or at cool room temperature.
Heat a thin sharp knife in hot water; wipe dry. Score a 4-by-4 grid, then cut straight through all layers, reheating and wiping between cuts. Lift out with parchment tabs; serve chilled or at cool room temperature.
06
Sensory cues of doneness
- Visual: three distinct tiers, dark nutty base, pastel custard, glossy chocolate, with clean, sharp cuts.
- Auditory: a crisp snap as the warm knife goes through the chocolate without squashing the custard.
- Olfactory: Dutch cocoa, toasted coconut, vanilla custard powder and sweet butter.
Check for three distinct layers and clean cuts: dark nut base, pastel custard and glossy chocolate. The chocolate should snap without crushing the custard; expect cocoa, coconut, vanilla and butter aromas.

Storing it

Layer between parchment in an airtight box and freeze up to 3 months. Thaw in the fridge 30 minutes before serving.

Troubleshooting

Muddy streaks between the layers.: Hot chocolate was poured over the custard and melted its butter. Cool the chocolate to lukewarm first.
A runny, over-sweet middle.: Instant pudding mix stood in for custard powder. Bird's is cornflour based and gives both the flavour and the structure.
The top shatters when cut.: A cold knife. Warm the blade in hot water and wipe it dry before every cut.

Substitutions

One-to-one swaps, with the technique change each one needs.

Ingredient substitutions

Ingredient	Replace with	Culinary impact and technique adjustment
Bird's Custard Powder	Cornflour plus 1 tsp vanilla and a pinch of turmeric for colour	Must be cornflour based to set the buttercream
Graham crumbs	Digestive biscuits or vanilla wafers, crushed fine	One-to-one. Same texture
Walnuts	Pecans, toasted almonds, or extra crumbs for nut-free	One-to-one

Scaling

Half, for 8

Use a 23 by 13 cm loaf pan. Chill times stay the same.

Double, for 32

Double everything in a 23 by 33 cm metal pan.

What to serve it with

A double espresso, to cut the buttercream
Fresh raspberries, for acid
An Okanagan late-harvest Riesling

Questions

What is Bird's Custard Powder?

An egg-free cornflour powder with vanilla and annatto, invented in 1837 by Alfred Bird for his egg-allergic wife. It is what makes a Nanaimo bar a Nanaimo bar.

Can I freeze them?

Yes, layered between parchment in an airtight box for up to 3 months.

Can they be gluten-free?

Use gluten-free graham crumbs in the base. The custard powder is naturally gluten-free.