Melt butter. Combine 2 cups flour and ½ cup powdered sugar, and then mix in melted butter. Pat down flat in pan. Bake for 10 minutes. Set aside
Purée ricotta in a food processor until smooth, about 1 minute. Add cream cheese, sugar, sour cream, egg, egg whites, almond extract, flour and salt; puree until smooth. Whisk 2 tablespoon hot water, cocoa powder and espresso powder in a bowl until well combined. Stir in chocolate chips. Stir 1 cup plain filling into chocolate mixture. Set aside. Pour remaining plain filling into prepared pan. Drizzle chocolate filling in a circular pattern over plain filling. Using a knife, make circular strokes to create swirls in the plain filling. Add 1 inch hot water to a shallow baking pan; place springform pan in baking pan. Bake until cheesecake is firm around the edge and slightly soft in the center, 45 to 55 minutes. Run a knife around inside of pan. Remove foil; let cool on a rack. Chill 6 hours or overnight before removing sides of pan.