Place strawberries and lemon juice in a medium sauce pan and cook over medium heat for 3 minutes, or until the strawberries have softened. Crush them with a fork and continue cooking for another 10-15 minutes, or until the strawberries have reduced to about half of the original volume. Skim any foam that forms on the top while cooking and discard it. Allow the strawberries to cool completely, then blend them in a blender until smooth.

In the bowl of a stand mixer, beat the butter for 2-3 minutes, or until it is light and fluffy. Add in 6 cups of the powdered sugar and the pinch of salt, then mix on low until it has all incorporated, scraping the sides of the bowl to make sure all of the butter is being mixed in.

Add the vanilla extract and strawberry reduction a little bit at a time until you have reached the desired flavor and color. If you have added most of it, then frosting may be thin and you may need to add extra powdered sugar for a spreadable consistency.

Spread or pipe onto cakes or cupcakes. Store any leftovers in the refrigerator. Bring to room temperature and whip again if needed before using.