In the bowl of a stand mixer combine everything but the strawberry pure. Beat on medium-high speed until smooth and creamy.
Puree strawberries in a blender and mash through a sieve, discard seeds and solids.
Measure ½ cup of the strawberry puree and beat it into the frosting over medium-high speed, scraping sides as needed. (If you have leftover strawberry puree it is delicious stirred into milk with a bit of sugar if you like.)
Use the frosting right away or refrigerate until ready to use. If the frosting is refrigerated before using it will need to come to room temperature and then be whipped again.
This frosting should be stored in a refrigerator even after it has been used for cupcakes or cake. It is ok to leave it unrefrigerated for several hours for serving – just don’t leave it on the counter on a cake for three days. Mmmmk?
Using ½ cup of strawberry puree in this recipe makes a good stiff buttercream for decorating. The flavor is bursting with fresh strawberry. If you want to use a bit more ¾ cup of puree will make a looser frosting with a slightly stronger flavor.