Start by preparing your pie crust if it’s not already baked. I usually blind-bake mine until it turns lightly golden and crisp. This step ensures the crust stays firm once the filling is added. Let it cool completely before moving forward.
In a saucepan, whisk together sugar, cornstarch, and water until smooth. Then add lemon juice, zest, and egg yolks while whisking continuously. Cook over medium heat until the mixture thickens into a silky consistency.
Once thickened, remove the pan from heat and stir in butter and vanilla extract. I always notice this step makes the filling extra smooth and glossy. Let it cool slightly before pouring it into the crust.
Spread fresh raspberries evenly across the baked crust. Pour the warm lemon filling over the berries, making sure they are fully covered. This creates a beautiful layered effect once sliced.
Place the pie in the refrigerator for at least 3–4 hours. I’ve found that chilling overnight gives the best texture. The filling firms up perfectly and slices cleanly.
Before serving, top with whipped cream if desired. I like adding a few extra raspberries on top for presentation. Slice and enjoy the refreshing, tangy flavor.