Preheat the oven to 180°c and line a muffin tin with patty pans.
Place the butter and sugar in a mixing bowl and beat on high until a pale and fluffy. Add the eggs and vanilla paste and mix well.
Sift the flour, baking powder, baking soda and salt into a separate bowl.
Mix the milk and the yoghurt.
Add the dry ingredients and the milk alternately, bit-by-bit, ending with the dry ingredients and mix well.
Fold in the sprinkles, being careful not to mix too much.
Spoon the mixture into the patty pans until 2/3 full. Bake for 18 to 20 minutes or until a skewer inserted into a cupcake comes out clean. Cool on a wire rack.
For the white chocolate frosting
Place the butter in a mixing bowl and beat on medium for about 3 minutes until light and fluffy. Add 1 cup of the icing sugar and mix well.
Take care to ensure that the chocolate has cooled. Add the chocolate, cream, vanilla and salt to the whipped butter and sugar and mix well.
Add the remaining icing sugar a little at a time until the desired consistency is reached.
Frost the cooled cupcakes and top with more sprinkles or unicorn and rainbow decorations.
Use good quality sprinkles!Be careful when adding your sprinkles. If you stir too much, the colour will bleed into your batter. You'll have badly tie-died cupcakes rather than pops of colour.Use real vanilla paste, sugar or essence, not imitation vanilla.