Vanilla cupcakes with rhubarb and custard butter cream

By Nikki & Jordan Shearer

Featured in Capital #64
Subscribe to get the real thing here

Everyone seems to have their favourite cupcake recipe, but we have never quite found one that we thought was perfect. So we have been experimenting with ideas to produce a cupcake that is not too sweet, not dry, and most importantly, easy to make.

Well, we think we’ve done it!

The tartness of the rhubarb compote is the perfect foil for the sweetness of the frosting, and filling the centre with the compote makes the cake moist and gooey. The trick for the buttercream is to make sure that everything is at room temperature, use a handheld electric mixer and don’t over-whisk. If the mixture splits, just add some melted chocolate, stir through, and magically the fat content of the chocolate will resurrect the buttercream to a silky smooth consistency.

Check out our Onespoon Instagram page for the chocolate cupcake version… either flavour could become your new fave!

Makes 12–15

Vanilla cupcakes


100g unsalted butter, softened
¾ cup caster sugar
2 eggs
2 Tbsp golden syrup
1 tsp vanilla extract
½  cup buttermilk
1 ¼ cup flour
1 ½  tsp baking powder
½ tsp baking soda
Pinch salt
Paper cupcake cases


Preheat oven to 180 ℃ fan bake, and place cupcake cases in a muffin tin.

In a mixer, cream butter and sugar until light and creamy.

Add eggs one at a time and beat together with golden syrup and vanilla extract. Beat in buttermilk until all ingredients are combined.

Sift in dry ingredients and gently fold through.

Pour mixture into liners, filling to just under three-quarters full, and bake for about 25 minutes or until a skewer in the centre comes out clean. Cool.

Rhubarb compote


6–8 stalks of rhubarb, washed and cut into 2cm slices
3 Tbsp caster sugar
1 Tbsp golden syrup
1 vanilla pod, halved lengthways and seeds scraped
3 Tbsp water


Preheat oven to 180 ℃. Mix together ingredients in an ovenproof dish, cover with tinfoil. Bake for 40– 50 minutes until rhubarb is soft. The liquid should have evaporated.

Set aside and cool. When cool, remove vanilla pod and blitz to a smooth pulp. Place in piping bag.

Custard buttercream


2 cups milk
1 vanilla bean, halved lengthways and seeds scraped
2 egg yolks
1 Tbsp cornflour
½ cup caster sugar
225g unsalted butter, softened and at room temperature
½ tsp vanilla extract
Custard (as per below steps 8–12)


Add all of the vanilla bean to milk, heating until bubbles start to form around edges. Remove from heat and remove vanilla pod.

In a mixer beat egg yolks, cornflour, and sugar until light and creamy.

Pour heated milk slowly into egg mixture and whisk together.

Clean saucepan and pour combined milk and egg mixture back into the pot.

Cook over medium heat, stirring constantly until thickened. Don’t overheat as egg will scramble! Remove from heat and pour into bowl. Cover with cling film, pressing film onto surface of custard to prevent a skin forming. Set aside at room temperature.

Using a hand mixer, beat butter and vanilla until light and fluffy. Gradually add custard two tablespoons at a time, slowly mixing to combine. This is where mixture could split, so don’t over-beat. Place in piping bag ready to decorate.


Scoop out small centre of each cupcake and pipe in rhubarb compote. Pipe buttercream on the top of each cake.

Decorate with your own sass… we used edible flowers, freeze-dried berries, crumble, and drizzled melted chocolate.


Sign up to our newsletter