Prepare for Baking:
Preheat your oven to 350°F (175°C).
Grease two 9-inch round cake pans and line the bottoms with parchment paper.
Make the Cake Batter:
In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
In a large mixing bowl, cream the butter and sugar together until light and fluffy.
Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
Mix in the sour cream and milk until combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the strawberry puree gently to ensure an even distribution.
Bake the Cakes:
Divide the batter evenly between the prepared pans.
Bake for 25–30 minutes or until a toothpick inserted into the center comes out clean.
Cool the cakes in the pans for 10 minutes before transferring them to a cooling rack to cool completely.
Prepare the Frosting:
In a large mixing bowl, beat the butter until creamy.
Gradually add powdered sugar, 1 cup at a time, mixing well after each addition.
Add the strawberry puree, vanilla extract, and salt, and beat until smooth and fluffy.
Assemble the Cake:
Place one cake layer on a serving plate and spread a generous layer of frosting on top.
Place the second layer on top and frost the top and sides of the cake.
Decorate with fresh strawberries if desired.