Preheat the oven to 350°F (175°C). Grease your cake pans and line the bottoms with parchment rounds. Sift together the flour, baking powder, and salt in a bowl and set aside.

In your mixer bowl, beat the room-temperature butter with the sugar on medium-high speed until light and fluffy, about 3–4 minutes. Scrape down the sides as needed.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla and lemon zest.

With the mixer on low, add one-third of the dry ingredients, then half the milk, another third of dry, the remaining milk, and finally the last dry ingredients. Mix until combined, but avoid overmixing.

Divide the batter evenly between the prepared pans. Smooth the tops with a spatula and bake for 22–28 minutes, rotating once halfway through, until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool the cakes in pans for 10 minutes, then invert onto a rack to cool completely.

For the strawberry filling, toss sliced strawberries with 2 tbsp sugar and 1 tsp lemon juice. Let sit 20–30 minutes until they release juices.

For a thicker filling, roast halved strawberries at 375°F (190°C) with 2 tbsp sugar for 12–15 minutes until syrupy, then mash gently and stir in cornstarch mixture.

Beat the butter on medium until creamy. Gradually add powdered sugar, then lemon juice, vanilla, and a pinch of salt. Adjust to taste.

Place one cake layer on your cake board and brush lightly with simple syrup if desired. Spread a thin layer of buttercream, then add a layer of strawberry filling.

Top with the second cake layer and crumb-coat with a thin layer of buttercream. Chill for 20 minutes to set.

Finish with a final coat of buttercream or leave the sides slightly exposed for a rustic finish. Decorate with fresh strawberries, lemon zest, and piped rosettes if desired.