1 cup (6 ounces) semisweet chocolate chips
2 eggs at room temperature
1 tablespoon sugar
1 cup very cold heavy whipping cream
1 teaspoon vanilla extract

Place medium mixing bowl in freezer to chill. Melt chocolate chips. In a large mixing bowl, beat eggs until foamy, sprinkle in sugar and keep beating for 3 minutes (until eggs are thick and very light in color). Scrape chocolate into egg mixture. Beat until just blended. Pour the cream into the chilled medium mixing bowl and add the vanilla. Beat the cream on high until it is very thick. Remove mixer and add about 1/4 of the whipped cream to the chocolate mixture. Lightly stir the cream into the mixture without beating all of the air out of the whipped cream. Fold the remaining cream into the batter until there are no streaks of white. Pour the mousse into six glasses or dessert bowls and chill at least 3 hours.