In a saucepan, combine the milk, heavy cream, and half of the granulated sugar (1/4 cup). Stir over medium heat until the mixture is warm but not boiling.
In a separate bowl, whisk together the cornstarch, remaining sugar, and salt. Gradually add the egg yolks and vanilla extract, mixing until smooth.
Once the milk mixture is warm, slowly pour it into the egg mixture while whisking constantly to temper the eggs. Return the combined mixture to the saucepan and cook over medium heat, stirring continuously until it thickens and begins to bubble. Remove from the heat and let it cool slightly. Add a few drops of red food coloring to achieve a lovely pink hue, then cover and refrigerate.
In a medium saucepan, bring the water, diced butter, sugar, and salt to a boil. Once boiling, remove it from the heat and stir in the flour all at once. Mix until the dough forms a ball and pulls away from the sides of the saucepan. Allow it to cool for a few minutes.
Add the large eggs one at a time, mixing well after each addition. The dough should be smooth and glossy. Use a pastry bag fitted with a round tip to pipe small mounds of dough onto a parchment-lined baking sheet, leaving space between each mound.
Preheat your oven to 400°F (200°C). In a small bowl, whisk the remaining egg with a tablespoon of water. Brush this egg wash over the piped dough to give it a beautiful sheen. Bake for 20-25 minutes until the puffs are golden brown and puffed up. Once baked, turn off the oven and crack the door, letting them cool inside for about 10 minutes.
Once cooled, use a sharp knife to poke a hole in the bottom of each puff. Fill your pastry bag with the pink cream filling and pipe it into each puff until you feel it getting heavy in your hand.
Arrange your Jigglypuff Pink Cream Puffs on a platter and serve them chilled or at room temperature. They’re sure to be a hit!