1. Preheat oven to 350°F. Have ready a large baking pan, and put a kettle of water on stove to boil.
2. In a large bowl, using an electric mixer on medium speed, beat cream cheese with flour and sugar until smooth. Add eggs, one at a time, beating well after each addition. Stir in ricotta, milk, vanilla, lemon juice and zest. Divide mixture among 8 6-oz. ramekins or custard cups and set each in baking pan.
3. Place pan in oven and carefully pour in enough boiling water to reach halfway up sides of ramekins. Bake until cheesecakes are set in center and not jiggly, about 45 minutes. Carefully remove baking pan from oven and let ramekins sit in water for 15 minutes. Remove ramekins to a wire rack and let cheesecakes cool completely. Cover each with plastic wrap and refrigerate for at least 4 hours before serving.
4. Top each cheesecake with berries or cookie crumbs, if desired, just before serving.