For Cake: MELT butter, chocolate chips, cocoa and corn syrup over very low heat, stirring occasionally. Remove from heat; cool 5 minutes.
WHISK together eggs and sugar in a large bowl. Slowly add melted chocolate, stirring well to incorporate. Add vanilla.
POUR batter into a greased 9-inch round cake pan.
BAKE at 350°F for 35 to 40 minutes, or until set. Cake should be firm in center but spring to the touch. Cool completely. For best results, refrigerate overnight.
SERVE each slice of cake topped with White Chocolate Mousse and fresh berries.
For Mousse: HEAT white chocolate and 2 tablespoons cream in a heavy saucepan over low heat until chocolate is melted. Transfer to a medium size bowl and cool until mixture just begins to thicken.
BEAT remaining cream until soft peaks form. Gently fold whipped cream and almond extract into chocolate mixture. Cover.
CHILL at least 2 hours.