Raspberry Curd

I had made lemon curd before, but not really any variations on it.  The idea for this raspberry curd came about as a cake filling, but it would also be good on cookies or other baked goods like scones.  It might seem like a lot of work but I think it's worth it.

Makes 1 1/2 cups

8 oz red raspberries
3 eggs
1/2 cup sugar
1 tablespoon cornstarch
6 tablespoons butter
Red food coloring, optional

1. Crush berries with a potato masher.  Line a strainer with two layers of cheesecloth, layered crosswise like a +, and place strainer over a measuring cup or bowl.  Pour crushed berries into cheesecloth in strainer, bringing cheesecloth up over berries.  Apply pressure to the bundle of berries.  Increase pressure, squeezing cheesecloth bundle any way you can, until 1/3 cup of raspberry juice has been extracted from the berries.
2. In small heatproof bowl, beat eggs until integrated.  Set aside.
3. In small saucepan, mix together sugar and cornstarch.  Stir until cornstarch is integrated into sugar.  Mix in raspberry juice and butter.  Place saucepan on medium heat and stir constantly until mixture thickens and bubbles.
4. Using a whisk, stir eggs constantly in bowl.  Stirring constantly, pour half of the hot raspberry mixture into the eggs.  Whisk quickly until eggs are incorporated into mixture.  Pour egg mixture back into saucepan with remaining raspberry mixture and stir very quickly until incorporated.  Return saucepan to heat and cook for 2 minutes.  Stir in food coloring, if using, to make the curd a pretty pink color. Pour curd into a container with a lid and place in refrigerator until cold.