Bring the water to a boil in a small saucepan over high heat.
Meanwhile, add the sugar to a small bowl. Using a paring knife, slit the vanilla bean down the center. Run the tip of the knife down the inside of each half of the vanilla bean pod to grab the "caviar", then add it to the sugar. Sprinkle the cornstarch over the sugar and vanilla, then whisk well to combine.
When the water comes to a boil, stir in the sugar mixture and reduce the heat to low. Simmer, stirring frequently, until the vanilla sauce thickens, 3-5 minutes. Remove the saucepan from the heat. Add heavy cream and butter, then stir with a silicone or wooden spoon until the butter melts.
Drizzle vanilla sauce over bread pudding or any other dessert and serve.
Notes
Want a thicker sauce? Let it simmer longer or whisk in an extra egg yolk for a creamy custard-like consistency.
Ingredient Notes:
To substitute vanilla bean, use 1 teaspoon of vanilla paste or 2 teaspoons of extract.
Light brown sugar is another option but will alter the color.
Recipe Variations:
Extra creamy: Swap whole milk for heavy whipping cream to create an ultra-rich and decadent vanilla custard sauce with a velvety texture.
Bourbon or rum-infused sauce: Add a splash of bourbon or rum for a warm, boozy twist that enhances the flavors of bread pudding, cakes, and pastries.
Vanilla bean paste upgrade – Use more vanilla bean paste instead of vanilla extract for a more intense vanilla flavor and those signature vanilla bean specks.
Egg yolk custard sauce: For a thicker, more traditional creamy custard, whisk in egg yolks and cook the sauce gently over low heat until it thickens.
Storing Instructions:
Bread pudding sauce must be refrigerated. When stored in an airtight container, it will keep for up to 5 days.
You can also freeze it for 2 or 3 months! Because it contains cream, let it thaw in the fridge rather than the countertop.