Preheat oven to 350.
Prepare cupcake pan with liners.
Combine cake mix and gelatin in large mixing bowl.
Add pureed strawberries, milk, butter, eggs, and vanilla extract to dry mixture.
Beat on medium speed until well blended.
Spoon into cupcake liners.
Bake for 20 minutes or until wooden toothpick comes out clean.
Allow to cool completely before frosting.
Allow butter and cream cheese to soften.
Sift powdered sugar.
Cream butter and cream cheese in large mixing bowl.
Add sugar, 1/2 cup at a time to mixture. Beat on medium to blend.
Add vanilla extract and continue to beat on medium for 1 minute.
If the frosting is too thick, add a small amount of milk and mix. If it's too thin, add more powdered sugar and mix.
Add frosting to piping bag and generously frost each cupcake.