1-First, preheat the oven to 325 degrees F and line three 8- or 9-inch round cake pans with parchment paper rounds, then spray the edges with cooking spray. In a stand mixer bowl, combine the cake mix, flour, sugar, and lemonade mix, then add the sour cream, melted butter, milk, and eggs. Beat for one minute, scraping the sides halfway through, and divide the batter evenly among the pans (about 2 cups each).

2-Bake for 20 to 25 minutes or until a toothpick inserted comes out clean. Let the cakes cool for a few minutes, run a knife around the edges, invert onto wire racks, remove the parchment, and cool completely. For the strawberry buttercream, beat the butter until smooth, then gradually add the powdered sugar and pureed strawberries, adding milk if needed.

3-Assemble by placing one layer on a platter, spreading frosting evenly, adding strawberry slices, and repeating for the other layers. Apply a thin crumb coat, chill in the freezer for 30 minutes, then add the final frosting layer and garnish with strawberries or other options like sprinkles or lemon slices. This method ensures a professional finish every time.