Make the Strawberry Purée:

In a blender or food processor, purée the strawberries until smooth. Transfer to a saucepan and simmer over medium heat for 10–15 minutes until thickened and reduced by half. Cool completely.

Prepare the Cake:

Preheat oven to 350°F (175°C). Grease and flour two 8-inch round cake pans or line with parchment.

Cream Butter and Sugar:

In a large bowl, beat the butter and sugar together until light and fluffy—about 3 minutes.

Add Eggs and Vanilla:

Beat in the eggs one at a time, followed by vanilla.

Combine Dry Ingredients:

In a separate bowl, whisk together flour, baking powder, and salt.

Mix Wet and Dry:

Add the flour mixture in thirds, alternating with milk, beginning and ending with the dry ingredients. Stir in the cooled strawberry purée just until combined.

Bake:

Divide the batter evenly between prepared pans. Bake for 30–35 minutes, or until a toothpick comes out clean. Let cool in pans for 10 minutes, then turn out onto wire racks to cool completely.

Make the Frosting:

Beat the butter until creamy. Gradually add powdered sugar, then mix in the strawberry purée, vanilla, and salt. Beat until smooth and fluffy.

Assemble the Cake:

Spread a layer of frosting between the two cakes. Frost the top and sides. Decorate with fresh strawberries if desired.