Blend ingredients: Combine 2 1/4 cups milk, 4 egg yolks, 2/3 cup sugar, 1/4 cup cornstarch, and 1/8 teaspoon salt in a blender or whisk until completely smooth.It may look foamy—don’t worry, the bubbles disappear when heated.
Microwave to start cooking: Pour the mixture into a large microwave-safe bowl (at least 2-quart capacity). Microwave on HIGH for 3 minutes.
Whisk and continue heating: Remove and whisk well. Then microwave in 1-minute intervals, whisking after each, until the mixture thickens and heavily coats the back of a spoon (usually around 6–7 minutes total, depending on your microwave).
Finish with flavor: Stir in 2 tablespoons butter and 1 teaspoon vanilla bean paste or vanilla extract) until melted and fully incorporated.
Cool and cover: Press plastic wrap directly on the surface to prevent a skin from forming. Let cool at room temperature or chill before using.
Notes
Variations:Banana Cream Pie: Layer sliced bananas with the vanilla pastry cream in a pre-baked crust. See recipe notes for tips on preventing browning.Coconut Cream Pie: Stir in ½ cup flaked coconut (sweetened or unsweetened) after adding the vanilla and butter. Pour into a baked pie shell, top with whipped cream, and garnish with toasted coconut.No blender or food processor? Use a whisk and some arm power instead of a blender. If you end up with any lumps, force the pudding through a strainer. It will be as smooth as silk.