Preheat oven to 350℉/180℃. Line muffin tin with 12 cupcake papers. Set aside.
In a medium bowl sift together flour, baking powder and salt. Set aside.
In a stand mixer fitted with the paddle attachment, beat together butter and sugar on medium speed for 3-4 minutes until light and fluffy. Scrape down the sides and the bottom of the bowl as necessary.
On medium speed, beat in the eggs one at a time, beating well after each addition. Add the vanilla extract and beat until combined.
With the mixer on low speed, add half of the dry ingredients and beat just until combined. Add the milk and beat until combined. Add the other half of the dry ingredients and beat slowly or fold by hand just until combined. Do not overmix. The less you mix, the lighter the cake will be. Fold in diced strawberries.
*To make strawberry puree, put a few strawberries (about 5) in a food processor or blender and process them until they are pureed.
Store cupcakes in the refrigerator, tightly covered, for up to 3 days. Allow to come to room temperature before serving.
Unfrosted cupcakes can be kept tightly covered at room temperature for up to 3 days or in the freezer for up to 2 months.