For the cupcakes:
Gently crush the strawberries to release the juices, blending the berries and the juice. Divide the berries in half, saving one-half for the frosting. Take 1 tablespoon from the berries reserved for the frosting and mix with enough water to measure ½ cup.
In a large mixing bowl add the flour, the cake mix and the strawberry gelatin. Mix together until it’s well blended. Add the ½ cup strawberry-water and the vegetable oil, blending together on low-speed.
Still using low speed, add the eggs one at a time, blending well after each one. Then beat the batter on medium speed for 2 minutes. Gently fold in the remaining portion of berries reserved for the cake.
Fill 24 lined muffin cups, each about ¾ full or pour the batter into a 13” x 9” x 2” cake pan that has been sprayed with a cooking spray. Bake the cake at 350-degrees for 25 to 30 minutes, cupcakes for about 20 minutes or until a toothpick inserted in the center comes out clean. Check the cupcakes around 18 minutes baking time.
Cool the cupcakes in the pan for about five minutes then transfer to a wire rack to cool. Make sure the cake or cupcakes are completely cool before frosting.
For the frosting:
Add the butter to a large mixing bowl and beat on medium speed until the butter is light and fluffy.
Add the vanilla extract and the kosher salt then blend into the butter on low speed.
Still using low speed, mix in 1 cup of the powdered sugar. Add 4 tablespoons of the reserved berries and the remaining powdered sugar, blending in a cup at a time.
Continue mixing until the frosting is smooth and creamy.
If you want a softer frosting add more of the reserved berries.