Egg Custard Filling

Ingredients

• 1 tablespoon butter 
• 0.3 cup cornstarch 
• 2  egg yolks 
• 1 cup milk 
• 0.3 cup sugar 
• 1 teaspoon vanilla extract 

Equipment

• bowl
• whisk
• plastic wrap
• double boiler

Directions

1. Combine sugar, cornstarch, egg yolks, and milk in top of a double boiler; stir well with a whisk. Cook over simmering water 8 to 10 minutes or until thickened, whisking constantly.
2. Remove from heat; whisk in butter and vanilla.
3. Pour custard into a bowl; place plastic wrap directly on top of custard to prevent a skin from forming. Chill at least 2 hours.