Preheat oven to 180 degree C.
Take flour, salt, baking powder in a bowl. Use a whisk to mix. Set aside.
Take sugar and eggs in a bowl. Use a electric beater to whip it for 1 min or so till combined.
Add vanilla and mix well.
Add in oil and mix well.
Add in half of the flour mix, half of the milk and mix.
Add remaining flour and remaining milk and mix well.
Now divide the batter between 7 bowls.
Add food colour into each bowl and mix gently.
Line muffin pan with cupcake cases.
Pour different colour batter into the muffin cases.
Place the cake pan in a preheated oven and bake the cake for 15 to 20 mins.
Don't over bake the cake.
Remove and cool completely.
Meanwhile whip the cream. Take cream powder and water in a large cold bowl. Whip it till stiff peaks form.
Now decorate the cupcake with the cream as you wish.
Chill the cake for few hours.
serve.