In a food processor blend ricotta and cocoa powder until completely smooth. Transfer to a large bowl.
Place egg whites, sugar and salt into the top of a double boiler (metal bowl over water). Cook and whisk constantly until the sugar dissolves and the mixture is warm, about 3 minutes.
Remove bowl from heat and beat with an electric mixer on high until stiff peaks form, about 5 minutes. Using a rubber spatula, gently fold egg white mixture into the bowl with ricotta until well combined.
Divide into 6 6 oz. ramekins or small glasses and refrigerate at least 3 hours. If desired, garnish with whipped topping and a sprinkle of sweetened chocolate powder!