Preheat the oven to 350 °F (177 °C). Line your cupcake pan with cupcake liners and set aside.
In a medium bowl, combine flour, salt and baking powder then set aside.
In a large bowl, using a handheld or standing mixer, beat the melted butter and sugar together until smooth.
Add eggs one at a time, mixing just to incorporate, then add vanilla and mix until smooth.
Add in the lemon juice, dry pudding mix and milk and combine.
Slowly add flour mixture to your wet ingredients and mix until just combined. But make sure to scrape down the sides and not leave pockets of dry ingredients.
Fill cupcake liners about 2/3 full. (this batter is fairly thick so I recommend using a spoon or cookie scoop to add the batter to each tin.
Bake for 15-20 minutes until a toothpick comes out clean. Then transfer the cupcakes to a cooling rack while making the frosting (they should be fully cooled before frosting)
To make the frosting, beat softened butter on high until light and fluffy (2-3 minutes).
Pour in strawberry puree and beat until mixed.
Then gradually add about 3 cups of powdered sugar to the strawberry butter mixture until combined.
Add remaining cup of powdered sugar until you get desired consistency and beat on high for about 2-3 minutes more.
Frost the cooled cupcakes using a spatula or pipe it on with a Wilton 1B Large Closed Star tip.
Notes
If you love lemon, you can add a bit of fresh lemon juice to the strawberry icing and adjust the powdered sugar accordingly to make up for the additional liquid.
Make sure that your strawberry puree has been blended down smooth with no big chunks of strawberry if you are planning to pipe your icing on or the pieces will get stuck in the piping tip.
Storage Instructions: Place cupcakes in an airtight container or in tight plastic wrap and leave on the counter for up to 3 days or and keep them refrigerated for up to a week.