01 -
Melt butter in a saucepan over low heat.
02 -
Add brown sugar and stir until completely dissolved.
03 -
Pour in milk while continuing to stir the mixture.
04 -
Turn heat to medium and bring to a gentle boil. Continue boiling for 2-3 minutes, stirring constantly.
05 -
Remove from heat and let cool until the mixture is warm but not hot.
06 -
Beat in 2 cups of powdered sugar until the frosting is smooth.
07 -
Add more powdered sugar if needed to reach your desired frosting thickness.
08 -
Mix in vanilla extract until well incorporated.
09 -
Use the frosting right away while it's still spreadable, as it will continue to thicken as it cools.