Grease and flour a 10-inch tube pan or standard size bundt pan.

Put the chocolate chips and water in a small saucepan set over low heat. Stir often until the mixture is melted and smooth. Remove from the heat and set aside to cool.

In a small bowl stir together the bananas, sour cream and vanilla until well blended.

In medium bowl, whisk together the flour, baking soda, salt and baking powder until well blended.

In a very clean large mixing bowl, beat the egg whites until they reach the soft peak stage. Gradually add 1/2 cup of the sugar, 2 tablespoons at a time until the egg whites are glossy and form stiff peaks. Set aside.

In another large mixing bowl beat the butter, the remaining 1 cup of sugar until creamy. Add the egg yolks and beat until light.

Alternately add the flour mixture and banana mixture to the butter/sugar/egg mixture, making sure the ingredients are combined before adding the next ingredient. Add 1/3 of the flour, then beat the mixture so the flour disappears. Then add 1/2 of the mashed bananas, and beat the mixture until they disappear. Continue this way, being sure you begin and end with dry ingredients.

Stir in the cherries.

Gently fold the egg whites into the cake batter, until no traces of egg white remain.

Gently scrape 1/3 of the batter into your prepared pan. Drizzle with half the melted chocolate. Repeat with another 1/3 of the batter and remaining chocolate and then top with remaining 1/3 batter.

Bake until a toothpick inserted in the center of the cake comes out clean, 45 to 55 minutes.

Remove from the oven and allow to cool for about ten minutes and then carefully remove the cake from the pan and place it on a wire rack to cool completely.