Preheat the oven to 180°C.
In a bowl, combine the flour, salt, and baking powder. Whisk well and set aside.
In a separate bowl, add the sugar and eggs. Beat with an electric mixer for about 1 minute until well combined.
Add vanilla extract and mix well.
Pour in the oil and mix until fully incorporated.
Add half of the flour mixture and half of the milk. Mix gently.
Add the remaining flour and milk, and mix until smooth.
Divide the batter evenly into 7 separate bowls.
Add different food colouring to each bowl and mix gently.
Line a muffin tray with cupcake liners.
Spoon different coloured batters into each liner.
Bake in the preheated oven for 15 to 20 minutes.
Do not overbake.
Remove from the oven and allow the cupcakes to cool completely.
While cooling, prepare the whipped cream: mix cream powder and cold water in a chilled bowl and whip until stiff peaks form.
Decorate the cooled cupcakes with the whipped cream as desired.
Chill the cupcakes in the fridge for a few hours.
Serve and enjoy!