In a medium saucepan, heat the milk over medium heat until it begins to simmer.

In a separate bowl, whisk together sugar, cornstarch, salt, and egg yolks until smooth and pale.

Slowly pour about half of the hot milk into the egg mixture, whisking constantly to temper the eggs.

Pour the tempered egg mixture back into the saucepan. Cook over medium heat, whisking constantly, until the custard thickens, about 5-7 minutes.

Remove from heat and stir in the butter and vanilla extract. Pour through a fine-mesh sieve into a bowl. Cover with plastic wrap pressed directly onto the surface and refrigerate for at least 4 hours.

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

In a large bowl, whisk together flour, sugar, baking powder, and salt. Add the softened butter and mix on low speed until the mixture looks like coarse crumbs.

In another bowl, whisk together the eggs, milk, and vanilla extract. Pour the wet ingredients into the dry ingredients and mix until just combined.

Divide batter evenly between the pans and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

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

Place one cooled cake layer on a serving plate. Spread the chilled custard evenly on top.

Top with the second cake layer. Arrange the sliced fresh strawberries over the top of the cake.

Chill for at least 30 minutes before slicing and serving to allow the custard to set firmly.