Combine 1 cup of ricotta, milk and egg yolks in a bowl. Sift flour and baking powder into ricotta mixture. Lightly fold together, using a metal spoon.
Whisk eggwhites in a clean, dry bowl until soft peaks form. Gradually whisk in 2 tablespoons of sugar. Gently fold eggwhites through ricotta mixture, until just combined. Mix together remaining ricotta and 1 tablespoon of sugar, until smooth.
Heat oil in a non-stick frying pan on medium. Wipe out excess with a paper towel. Cook 1/4-cup measures of batter on low for 2 minutes each side, until golden and cooked through. Keep warm. Repeat with remaining batter.
Meanwhile, combine passionfruit pulp with remaining sugar in a small serving jug. To serve, stack 2 ricotta cakes on a warm plate. Dollop with whipped ricotta and pour over passionfruit. Serve immediately.
Ricotta cakes are ready to turn when surface bubbles are beginning to burst.