01 - Preheat oven to 350°F (175°C). Grease two 6-cavity donut pans generously.
02 - In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt until evenly distributed.
03 - In a separate bowl, whisk together the whole milk, eggs, melted butter, and vanilla extract until smooth.
04 - Pour the wet ingredients into the dry ingredients and fold gently until just combined. Be careful not to overmix.
05 - Spoon the batter into the prepared donut pans, filling each cavity approximately three-quarters full.
06 - Bake for 10 to 12 minutes, until a toothpick inserted comes out clean and the donuts spring back when lightly touched.
07 - Allow the donuts to cool in the pans for 5 minutes, then transfer to a wire cooling rack to cool completely.
08 - Beat the softened butter with an electric mixer until creamy. Gradually add the sifted powdered sugar, beating until light and fluffy.
09 - Add the strawberry puree, vanilla extract, and a pinch of salt. Beat for 2 to 3 minutes until the frosting is smooth and airy.
10 - Once the donuts are completely cool, spread or pipe the strawberry buttercream evenly over each one.
11 - Top with thinly sliced fresh strawberries or sprinkles if desired. Serve at room temperature.