Add softened butter into your stand mixer or bowl
Beat butter on medium to high in a stand mixer for 3 minutes until fluffy
Just before the end of 3 minutes, add vanilla, 3 tbsp milk to butter, keep beating
Reduce to medium, pour in one cup of sugar at a time
Add food coloring if you wish
If the frosting is still too stiff add 1 tbsp of milk at a time and beat until fully incorporated
Spread on cake or cookies
Add sprinkles
Using an airtight container, store in the fridge for 2-3 days or freeze to keep for up to 2 months
Bring to room temperature, and beat before the frosting to restore the original texture
