Gluten-free orange and rhubarb cupcakes

Carrying on with one of my baking challenges on a gluten-free theme: a theme in which I am aiming for bakes that you would not otherwise know are gluten-free and can stand up against their non-gluten-free counterparts. This time, cupcakes.

I just adapted my usual cupcake recipe, and this version gives very light, moist sponges with a subtle hint of orange.  For these, I decided to top them with a little orange curd and an indulgent, but not sickly-sweet, blend of orange and rhubarb buttercream: we picked a load more rhubarb so I might as well get creative with it. As with many of my cakes, I do love using fruit purées and the like in icings as they give a natural zingy flavour.

Multi-tone icing:

– split a plain buttercream into two (or more) and then flavour and colour each separately. – spoon one flavour into one side of the piping back and the other flavour in the other half of the bag for a two-tone effect. Squeeze lightly until some of the icing comes through the nozzle in two tones (you will probably get an inch or two that is one colour before you see a distinct multi-tone effect). Fill the bag similarly if you are going for more colours. – pipe the buttercream over the cupcakes.

Simple variations:

For lemon cupcakes, replace the orange zest with lemon zest and omit the orange oil. In the buttercream, use lemon curd instead of orange curd. I like to use a mixture of lemon buttercream and strawberry buttercream.

For chocolate cupcakes, omit the orange zest and replace 20g of the gluten-free flour with 20g cocoa powder. In the icing, omit the curd and beat in 100g melted and cooled dark chocolate.

Gluten-free orange & rhubarb cupcakes: makes 12 cupcakes

For the sponge:

• 120g gluten-free plain flour
• 120g golden caster sugar
• 1 ½ teaspoon gluten-free baking powder
• a pinch of salt
• 40g unsalted butter, melted
• 120ml milk
• 1 large egg, at room temperature
• grated zest of one orange
• ½ teaspoon orange oil

For the buttercream:

• 150g icing sugar, sifted
• 150g unsalted butter, softened
• 2-3 tablespoons milk
• 4 tablespoons good quality orange curd
• 2 tablespoons rhubarb purée
• a few drops of red and orange food colouring, optional

(1) Preheat oven to 160C(fan).

(2) Sift the flour and baking powder into a large mixing bowl. Add the sugar, salt, orange zest and orange oil and mix well.

(3) Whisk the egg, milk and melted butter together and pour over the rest of the mix, stirring well until there are no lumps. You should have a fairly thick batter at this point.

(4) Pour into cupcake cases, coming to just under half-full and bake for 15-20 minutes until well risen and golden-brown on top. They should feel springy to the touch. Remove from the oven and cool in the tins. Spread a little of the orange curd over the top of each cake.

(5) Make the buttercream: put the icing sugar and butter in a large bowl and beat very well until incorporated. Add about half of the milk and beat in well. Add the rest of the milk and beat for about 5 minutes or so until very light and almost moussey: doing this in an electric míxer is easiest.  The buttercream should be very smooth.

(6) Split the buttercream into two portions: add the remaining orange curd to one portion and beat well to incorporate. Add the rhubarb purée to the other portion, along with a few drops of red food colouring, if using. Pipe or spoon the buttercream over the cupcakes. NB: the rhubarb purée was simply some rhubarb that was cooked down with a little sugar and some water until soft, before blitzing, straining and cooling. Although very sharp on its own, when mixed with buttercream it adds just a little piquancy which works well with the richness of the rest of the cupcake.