Banana Split Cheesecake with Strawberry Sauce

INGREDIENTS

• 1 1/2 cups cookie crumbs (chocolate wafers, graham crackers, nilla wafers, etc.)
• 2/3 cup plus 6 tablespoons sugar
• 5 tablespoons unsalted butter, melted
• 1 pound cream cheese (not low-fat or whipped)
• 1/2 cup mashed ripe banana (1 to 2 bananas)
• 1/4 cup sour cream
• 2 tablespoons unbleached all-purpose flour
• 4 eggs
• 1 ounce unsweetened chocolate, melted
• 2 cups fresh strawberries
• whipped cream and chopped walnuts for garnish (optional)