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

Whisk flour, baking powder, and salt together.

Cream butter and sugar until light and fluffy.

Beat in eggs one at a time, then add vanilla.

Alternate adding dry ingredients and milk, mixing just until combined.

Divide batter evenly and bake 25–30 minutes until a skewer comes out clean. Cool completely.

Heat milk with vanilla until steaming. Remove from heat and infuse 15 minutes.

Whisk egg yolks, sugar, and cornstarch until pale.

Temper with warm milk, return to pan, and cook until thick.

Stir in butter and vanilla. Strain, cover with plastic wrap touching surface, and chill 3–4 hours or overnight.

Dice strawberries. Optional: toss with sugar and lemon juice and rest 15–30 minutes.

Whip cold cream until thickened, then add powdered sugar and vanilla. Beat to stiff peaks. Chill until needed.

Heat sugar and water until dissolved. Cool completely.

Level cake layers. Brush with simple syrup if using.

Place first layer on serving plate. Pipe whipped cream border.

Fill with half the custard and strawberries.

Add second cake layer and repeat.

Apply a thin crumb coat and chill 15–20 minutes.

Frost fully and decorate with whole or halved strawberries. Chill 1–2 hours before slicing.