In a large bowl, using a hand-mixer, combine the ricotta, mascarpone, cream, cognac and sugar until light and creamy. Fold in the mini chocolate chips.
Pour the coffee into a shallow dish. Dip 2 ladyfinger halves into the coffee and arrange them on the bottom of a shallow glass serving cup. Liberally top with some of the cheese mixture. Repeat with another layer of dipped ladyfingers and cheese. Dust with cocoa powder. Repeat with the remainder of ingredients to make a total of 4 individual servings. Allow to cool before serving.