01 - Preheat oven to 350°F. Grease two 6-cavity donut pans and set aside.
02 - In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt until evenly distributed.
03 - In a separate bowl, whisk together the whole milk, eggs, melted unsalted butter, and vanilla extract until smooth.
04 - Pour the wet mixture into the dry ingredients and stir gently until just combined. Be careful not to overmix, as this can make the donuts dense.
05 - Spoon the batter into the prepared donut pans, filling each cavity approximately three-quarters full.
06 - Bake for 10 to 12 minutes, or until a toothpick inserted into a donut comes out clean and the tops spring back when lightly touched.
07 - Allow the donuts to cool in the pans for 5 minutes, then transfer them to a wire cooling rack to cool completely before frosting.
08 - Beat the softened unsalted butter with an electric mixer until creamy and pale. Gradually add the sifted powdered sugar, beating continuously until light and fluffy.
09 - Add the strawberry puree, vanilla extract, and a pinch of salt to the buttercream. Beat for 2 to 3 minutes until the frosting is smooth, light, and spreadable.
10 - Once the donuts are completely cool, spread or pipe the strawberry buttercream generously on top. Garnish with thinly sliced fresh strawberries or sprinkles if desired.