Preheat oven to 180C. Lightly grease the top and bottom of your cake pop pan.
Beat butter and sugar until well combined. Add eggs, salt, vanilla, flour and milk, and mix on low until combined. Increase speed to high and mix for 3 minutes.
Separate mixture into 4 bowls and tint with gel colours. Mix gently to combine.
Fill the wells of the cake pop pan with small amounts of each colour – only fill the pan level with the top or just below
Bake for 15-20 minutes, then remove from oven and cool on a wire cooling rack. Repeat with any remaining mixture. Allow to cool completely.
Melt about 40g chocolate. Dip the tip of the cake pop sticks into the white chocolate and insert into the cake balls about half-way. Allow to set. This can be sped up by placing the cake balls in the fridge or freezer.
Melt the remaining chocolate. Dip cake balls carefully into the chocolate until covered. Carefully lift cake ball free of the chocolate, let the excess chocolate drip off. Swirl and tap gently if needed.
Once chocolate is set, decorate with Queen Writing Icings to create little rainbows.
TIP Use a deep, narrow cup for dipping. The melted chocolate/candy coating should be deep enough to submerge the cake ball completely to avoid having to twirl it around.
TIP Have a block of foam ready to hold up cake pops after dipping in chocolate. To decorate with sprinkles, do so before the chocolate sets.