Using a food processor or blender, process the freeze-dried strawberries into a powdery crumb. You should have around 1/2 cup. If it’s not grinding down fine enough, you can sift it with a fine mesh sieve to rid larger seeds/pieces. Set aside.

In a large bowl using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter on medium-high speed until creamy, about 2 minutes. Add confectioners’ sugar, strawberry powder, heavy cream/milk, and vanilla. Beat on low speed for 30 seconds, then switch to high speed and beat for 2 minutes. Taste. Add 1–2 more Tablespoons of heavy cream/milk if needed to thin out, if desired. (I usually add at least 1 more.) Add a pinch of salt if frosting is too sweet.

Use immediately or cover tightly and store for up to 1 week in the refrigerator or up to 3 months in the freezer. After freezing, thaw in the refrigerator then beat the frosting on medium speed for a few seconds so it’s creamy again. After thawing or refrigerating, beating in a splash of heavy cream or milk will help thin the frosting out again, if needed. (It stiffens in the refrigerator.)