The key ingredients for Raspberry Custard Pastry include puff pastry, fresh or frozen raspberries, milk, cornstarch, egg yolks, sugar, vanilla extract, and butter. Each ingredient plays a vital role in creating the essential flavor and texture of the pastry. The puff pastry is the star of the dish, providing a light and flaky base that contrasts beautifully with the smooth and creamy custard filling. Raspberries contribute a burst of tartness that balances the sweetness of the custard and adds vibrant color to the pastries. The combination of milk and cornstarch thickens the custard, while egg yolks create a rich and luxurious texture. Sugar enhances the overall sweetness, and vanilla extract adds depth, making the pastry more aromatic. Butter, when incorporated, adds richness and a glossy finish to the custard. Understanding these ingredients will help you appreciate the balanced flavors in this delightful dessert.