Beat ricotta and cream cheeses with electric mixer until smooth. Add sugar and vanilla bean paste; beat until well blended. Divide mixture evenly between 2 mixing bowls.
Combine 1-1/2 cups cookie crumbs and milk in separate bowl, stirring until milk is absorbed. Fold mixture into 1 bowl of the cheese mixture. Fold lemon zest into second bowl of cheese mixture. Spoon each mixture into separate pastry bags fitted with small round tips.
For each serving: Pipe 1-1/4 oz. of each mixture into serving bowl; swirl to combine. Sprinkle with a small amount of the remaining cookie crumbs.