Preheat oven to 350 degrees F. Line cupcake pan and set aside.
Whisk together flour, salt and baking powder; set aside.
Beat together melted butter and sugar until smooth.
Add eggs one at a time, then add vanilla and mix until smooth.
Mix in lemon juice, zest and milk.
Slowly add flour mixture and mix until just combined.
Fill cupcake liners about 2/3 full.
Bake for 18-20 minutes. Let cool completely before frosting.
To start the frosting, beat butter on high until light and fluffy (2-3 minutes).
Slowly add about 3 cups of powdered sugar. Pour in strawberry puree and beat until mixed.
Add remaining powdered sugar until you get desired consistency and beat on high about 2-3 minutes.
Frost cupcakes and enjoy!