Preheat a fan-forced oven to 160C (320F) or 180C (356F) for a conventional oven. Line a cupcake tin with cupcake liners.
In the bowl of a stand mixer fitted with the paddle attachment, add the flour, baking powder, caster sugar and salt. Turn mixer on low speed and allow it to mix for a couple minutes to help everything combine well (alternatively you may do this by sifting the ingredients together). Add the softened butter and let it mix until it resembles a fine sand like texture.
Next, add milk, eggs, yogurt, mango essence, oil and vanilla extract in a large jug and whisk well.
Add wet ingredients to dry ingredients in a slow and steady stream until no dry ingredients are visible. Scrape down the bowl and mix for another 20 seconds.
Separate about 3 tsp of batter into a small bowl. Add blue and black food gel and mix until well combined. Fit the end of a piping bag with a small round tip.
Pipe long strips from bottom to top along the inside of your cupcake liners. Alternatively you can used striped cupcake liners.
Fill each cupcake liner 3/4 of the way with the rest of the batter (using an ice cream scoop to transfer the batter into the cupcake liners makes this a quick and easy process otherwise you can use two tablespoons).
Bake for 20-25 min or until a toothpick inserted comes out clean. Allow them to cool completely on a wire cooling rack before frosting.
To prepare frosting add red food gel and strawberry essence and mix until well combined.
Fit the end of a piping bag with a medium sized round tip and frost a swirl of frosting on top. Finish with a sprinkle of both glitters.