In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on medium-high speed for about 5 minutes.
Turn the mixer down to low speed and gradually add in the confectioners' sugar until it is completely incorporated. Add in vanilla and 3 tablespoons of the strawberry puree, mix until incorporated. Turn off the mixer and check the buttercream for taste and texture. Gradually add in the last 2 tablespoons of strawberry puree until you reach the desired level of strawberry flavor. Please note that adding more than the recommended 5 tablespoons could result in a thinner frosting. Turn the mixer back up to medium-high speed and beat the mixture for about 3-4 minutes or until light and fluffy.
Spread or pipe onto cake or cupcakes.
Notes
Store unused frosting in an airtight container in the fridge for up to 2 days or in the freezer for up to a month. Bring to room temperature and whip with a mixer for 1-2 minutes before using.Makes enough frosting for 24 cupcakes or a 9-inch layer cake