In a stand mixer, beat room temperature butter until creamy. On low, slowly add icing sugar. Make sure to do this on low or you will be wearing, and inhaling a your sugar.
When combined and creamy, add vanilla and lemon. Then break up berries by hand and drop them into the mixer while it runs on low. This will flavor and color the frosting. Just remember to use a large opening piping tip when frosting because the seeds can clog small tips.
When cupcakes are totally and completely cooled, frost. Add whole and/or crushed pistachios for garnish, as well as some whole raspberries.