In a medium pot combine the egg yolks, sugar, lemon juice, and butter.

Put the pot over medium heat and cook whisking constantly until the mixture thickens. About 10 minutes.

Using a spatula remove the lemon curd from the pot and into a medium-sized metal bowl.

In a separate bowl beat the egg whites until they reach stiff peaks.

Fold the egg whites into the lemon curd one third at a time.

Divide the lemon mousse among 6 dishes and chill for two hours.

Serve with fresh raspberries.