Pour oil into a large pot or dutch oven. Attach candy thermometer. Heat oil to 355F |180C
While the oil heats, make the batter. In a medium sized bowl, stir together ricotta/yogurt, eggs, sugar, lemon juice and zest.
Add flour, salt and baking powder*. Mix until smooth.
Drop zeppole into hot oil using a 2 tbsp cookie scoop, or measuring spoon. Fry 4-6 at a time, for about 4 minutes, or until they turn a deep golden brown. (Note: they should flip on their own, but if one gets stuck flip around the 2 minute mark.)
Keep an eye on the oil temperature, making sure it stays around 355F |180C.
Remove the Zeppole to a paper towel lined tray. Before serving, transfer to a clean platter and dust with powdered sugar.