• Preheat oven to 170°C. Line a 12-hole muffin tin with paper cases.
• In a large mixing bowl sift together cake flour, bicarbonate of soda, salt, and cocoa powder. Set aside.
• In the bowl of a stand mixer or using a hand mixer beat butter and sugar together for 1-2 minutes. Add in oil and beat for 3 minutes or until light and fluffy.
• Add egg, vanilla extract, red gel food colouring and vinegar. Mix until well combined, scraping down the sides of the bowl as needed.
• With mixer on low, alternately add the flour mixture and buttermilk mixture, beginning and ending with the flour mixture.
• Fill the cupcake liners ¾ full with batter.
• Bake for 20 to 22 minutes or until the tops of the cupcakes spring back when touched and a toothpick inserted into the center comes out clean.
• Remove the cupcakes from the oven and place them on cooling rack for 10 minutes. Carefully remove the cupcakes from the pan and leave them to cool completely on a rack before frosting.

White Chocolate Cream Cheese Buttercream

• Place chocolate callets or chunks in a heat-proof bowl. Melt in 30 seconds bursts in the microwave until melted. Set aside to cool.
• Beat butter until light. With the mixer on low speed slowly add icing sugar and beat until well combined. Mix in vanilla extract and salt. Add cream cheese, whipping, or double cream and melted chocolate and beat until fluffy.
• Cover and store in the fridge. It can be kept for up to 5 days in the fridge or 3 months in the freezer.

Assemble the Cupcakes

• Fit a piping bag with a piping tip. I used a Wilton Star Tip 1M. Fill the piping bag with cream cheese buttercream.
• Hold the piping bag over the cupcake and slowly pipe a spiral starting in the centre and working your way out,
• Store in an airtight container in the fridge for up to 5 days.