Makes about 2 cups

Ingredients
1 6 oz Container Driscoll’s Blackberries
Zest from 3 large lemons
½ cup lemon juice
¾ cup sugar 
5 egg yolks
Pinch of salt
5 tbsp unsalted butter, at room temperature

Directions
Add blackberries and lemon juice to a small saucepan and set over medium heat. Cook until the blackberries begin to pop and the liquid begins to bubble, about 5 minutes. Set a fine mesh strainer over a mixing bowl and strain the blackberry and lemon juice into the bowl, pressing down of the berries with the back of a spoon to get every last bit of berry.
 
Set up a double boiler by placing a heat safe bowl over a pot of simmering water. Make sure the water is not touching the bottom of the bowl. Remove the bowl and add the blackberry lemon mixture, lemon zest, egg yolks and whisk until smooth.  Place the bowl back on top of the pot of simmering water and continue whisking constantly for about 10 minutes, or until the mixture thickens. Remove from heat and stir in the butter 1 tablespoon at a time until well combined. 
Let cool, then place in the refrigerator for at least 2 hours before using.