Instructions

To make the cupcakes:

1. Preheat your oven to 350F/180C and line a 12 count muffin tin with cupcake liners. 
2. Put the flour, baking powder, baking soda, salt, and xanthan gum (if using) in a mixing bowl, whisk together to combine. Set aside
3. In a stand mixer fitted with the paddle attachment, or a handheld electric beater, beat the butter on a high speed until light and fluffy, about 2-3 minutes. 
4. Add the sugar and beat until fluffy, about 2 minutes
5. Turn the mixer speed down to medium, and add the eggs one at a time, beating between each addition. 
6. Stir the vanilla into the buttermilk. 
7. Turn the mixer speed down to low, and add 1/3 of the flour mixture, beat to combine. Then add 1/2 of the buttermilk and beat to combine. Add another 1/3 of the flour mixture, beat to combine, then add the other 1/2 of the buttermilk and beat to combine. Add the last remaining 1/3 of the flour mixture and beat until just combined. 
8. Spoon the cupcake batter into your liners, filling about 3/4 full (approx 2.5 tbsp of batter per cupcake).
9. Bake for 15-18 minutes, until they are springy to touch and a skewer comes out clean.
10. Cool in the tin for 5 mins, then turn out on to a wire rack to cool completely.

To make the buttercream:

1. In a stand mixer fitted with a paddle attachment, or a handheld electric beater, beat the butter on a high speed until very pale, about 8-10 minutes.
2. Add the confectioners sugar, cream and vanilla. Turn the mixture on to its lowest setting and beat until  combined (this is to avoid the sugar cloud!). Turn the mixer back up to high and beat until fluffy - about 3-5 minutes. 
3. Divide the buttercream into 4 bowls, with one bowl having approximately twice as much as the other three.
4. Add 4 drops black colouring to the bowl with the most buttercream in, stir until evenly coloured. Add more colouring as needed to get desired shade. 
5. Add 3 drops of neon pink, purple, and teal (or other neon colours of your choice) to the remaining bowls - one colour per bowl of course! Stir until evenly coloured. Add more colouring as needed to get desired shades. 

To assemble the fireworks cupcakes (see video for visual instruction):

1. Spoon each colour of buttercream into a separate small piping bag and snip off the end. Place these piping bags in a large piping bag fitted with a large star tip. Set aside.
2. Cut a hole from the centre of each cupcake, and fill with popping candy. From the cut outs, cut the top off and place back over the hole to act as a lid. Eat the rest of the cut outs :D 
3. Take your piping bag and pipe a little out into a bowl to ensure all four colours are coming out. Pipe a swirl on top of each cupcake
4. Sprinkle with more popping candy