Make sure the butter and (washed) strawberries are at room temperature.
Mash or puree the strawberries using a stand or immersion blender.
Take the butter and start whipping in a stand mixer using the paddle attachment, or in a handheld mixer until light and fluffy, about 5-7 minutes.
Add the confectioners sugar and mix for another 2 minutes.
Add the strawberry puree and mix for another 2 minutes.
Scoop the strawberry butter into a jar or another container. Store in the refrigerator for up to one week in a airtight container or covered with saran wrap.
When ready to use, remove from the refrigerator for at least 10 minutes to soften before using.
Notes
The recipe calls for ¼ cup of strawberry puree, which equates to about 5 medium strawberries. This recipe is a great way to use up strawberries that are starting to get mushy and need to be used before going bad.