Step 1

Pre-heat the oven to 180 ºC (350 ºF) and line a cupcake baking tray with 12 cupcake cases.

Step 2

In a bowl, melt together the butter and white chocolate, and allow to cool until warm.

Step 3

Add the caster sugar and mix with a whisk, a hand mixer with beater attachments, or a stand mixer.

Step 4

Add the eggs, one at a time, mixing after each addition until fully incorporated.

Step 5

Sift together the flour of choice, salt, baking powder and baking soda.

Step 6

Add the flour mixture and milk, and mix until the flour is only just incorporated and a smooth batter forms. Do not over-mix.

Step 7

Using an ice cream scoop or a spoon, fill the cupcake cases about 3/4 full with the cupcake batter.

Step 8

Bake in the pre-heated oven at 180 º C (350ºF) for 23 – 25 minutes or until golden brown and an inserted toothpick comes out clean.

Step 9

Remove the cupcakes from the cupcake baking tray and allow to cool before decorating.

Step 10

In a saucepan, bring the blueberries and lemon juice to a boil. The blueberries will soften and release their juice.

Step 11

Simmer until the juice is significantly reduced in volume and a thick, jam-like consistency is reached (about 5 – 10 minutes).

Step 12

Pass the cooked blueberries through a sieve to remove their skins. Use a spatula or spoon to press the blueberry "jam" against the sieve so as to extract all of the reduced juice.

Step 13

Allow the reduced juice to cool completely before adding it to the buttercream. If it is too warm, it will melt the butter, which you most definitely don't want.

Step 14

Using either a hand mixer with the beater attachments or a stand mixer with the paddle attachment, beat the butter until pale and somewhat fluffy.

Step 15

Add 1/2 of icing/powdered sugar and beat the butter/sugar mixture on medium to high speed for about 5 minutes.

Step 16

Add the remaining 1/2 of icing/powdered sugar and beat the mixture for a further 10 minutes (5 minutes medium speed, 5 minutes high speed). At this stage, the buttercream should be very pale, creamy and fluffy.

Step 17

Add the cooled reduced blueberry juice, all at once, and beat the buttercream at high speed for 1 minute.

Step 18

Using a spatula, scrape along the mixing bowl walls to check that all of the blueberry juice has been incorporated. If it hasn't, mix again for 1 minute.

Step 19

Using an 18 mm open star nozzle and piping bag, pipe the blueberry buttercream on top of the white chocolate cupcakes. (Or use any nozzle you fancy. Or don't use a nozzle at all and just dip the cupcakes into the buttercream on their way to your mouth.)

Step 20

Sprinkle with white chocolate shavings (or any sprinkles of choice).

Step 21

The cupcakes keep well in a closed container in a cool dry place for about 3 – 4 days. (Hah, yeah, right. A day... at most.)