Preheat oven to 350F (175C). Grease a 10" round pan and line bottom with parchment paper.

Chop unsweetened chocolate and place in a large bowl with chocolate chips. Add melted butter. Heat water and 330g (1.5 cups) sugar in a saucepan until boiling, and then pour over chocolate. Stir until smooth.

In a separate bowl, whip eggs with remaining 55g (1/4 cup) sugar until thick. Fold into chocolate mixture. Pour batter into 10" pan.

Place 10" pan in a shallow pan in the oven and fill the cookie sheet with water.

Bake at 350F (175C) for 40 to 50 minutes. Remove from oven. Cool and refrigerate for several hours. Be extremely careful not to burn yourself on the hot water when removing the sheet pan from the oven.

Dip the pan in hot water to remove cooled cake. Garnish with whipped cream and serve.