Place the ricotta into a sieve and let it drain while you start preparing the strawberry filling.
To make the Raspberry Filling: In a 3- quart sauce pan over low heat, cook the raspberries, sugar, cornstarch and a tablespoon of water for about 5 minutes, or until the filling thickens up.
Process the berry mixture in the food processor until it's smooth.
Fill a pastry bag with a large tip, with the raspberry filling. This way you'll be ready to fill the zeppole when they come out of the oil.
Heat the two inches of oil in a Dutch oven, using a deep fry thermometer. It is ready when it reaches 350°.
Meanwhile, sift together the flour, salt, sugar and baking powder into a large bowl.
In a second bowl, stir together the ricotta, eggs, and vanilla. Then, add it all to the bowl with the flour, and stir until just combined.
Using a tablespoon drop in 6 zeppole at a time. Cook them until they are dark golden brown and cooked all the way through. Use a long spoon to turn them over. Drain them on a rack, and dust them with powdered sugar.
Using a knife, cut a small slit in the top of each zeppole. Use the pastry bag to insert some filling in each zeppole.
Serve right away.