Slowly pour the egg-cream mixture back into the saucepan. Whisk.Turn the flame on low and cook until the base thickens slightly, about 2 to 3 minutes. Be careful not to overcook, as the mixture will curdle.
Strain through a fine-mesh strainer and chill for 2 to 3 hours or overnight.
For the Boysenberry IceCream: Make a boysenberry puree by tossing the berries and the sugar together and setting the mixture in a warm place to macerate for 1 hour. You canheat the mixture in a 200 degree oven for 30 minutes to speed up the process.