Directions

1. Preheat oven to 350 degrees F. Place chocolate and butter in a microwave-safe bowl. Heat in a microwave oven at 50 percent power, stirring twice, until chocolate is soft, 3 to 4 minutes total. Remove from oven; stir until mixture is smoothly blended.
2. Add egg yolks and flour to chocolate mixture; whisk until smooth.
3. In a bowl, combine egg whites and cream of tartar. Beat with a mixer on high speed until whites are foamy. Beat, gradually adding sugar, until whites hold stiff, glossy peaks.
4. Add about one fourth of the beaten whites to chocolate mixture; stir to mix. Add remaining whites and gently fold into chocolate mixture until evenly incorporated. Scrape mixture into an 8-inch cake pan with removable rim. Spread batter smooth.
5. Bake until torte puffs slightly and center barely jiggles when pan is gently shaken, 18 to 20 minutes. Cool at least 1 hour in pan on a rack (torte will sink slightly).
6. Slide a sharp knife between torte and pan. Remove pan rim.
7. Cut torte into wedges and transfer to plates. Spoon whipped cream onto each serving and garnish with berries.