Place butter in bowl of mixer, and attach paddle flat beater. Mix on medium speed until butter breaks up and is starting to look smooth.
Add vanilla and salt; mix for 30 seconds until combined.
Add in heavy whipping cream.
Measure powdered sugar on scale. Slowly add to the mixer, 1 cup at a time.
PRO TIP: Start the mixer speed back up slowly after adding the cup of powdered sugar, otherwise, pull out the mop.
Once ingredients are all mixed, turn the mixer to medium high and set timer for five minutes.
Incorporate in the crushed raspberries. Use in your macarons!
NOTE: American Buttercream will keep up to two weeks in the fridge, and one day at room temperature.