Carefully remove the stamen (the pollen-producing center) from the center of each blossom.Gently wash and pat dry the blossoms.
In a bowl, mix together the ricotta, Parmesan and basil, and then season with salt and pepper, to taste.
Spoon a heaping teaspoon of the ricotta mixture into the center of each blossom, twisting the tips of the petals to close it. Set aside.
In another bowl, whisk together the flour and fine sea salt.
Add the olive oil, egg and water and whisk into a batter.
In a heavy-bottom pan, pour the canola oil to a depth of 2 inches.
Heat the oil over medium-high heat until it reaches 375° or is shimmering.
One at a time, gently dip the stuffed blossoms into the flour batter and turn to coat completely.
Using a slotted spatula, lift the blossoms from the batter, allowing the excess batter to drip off, and carefully lower them into the hot oil.
Fry in batches of 4—placing each blossom at least 1 inch apart in the pan.
Flip after 2 minutes, or until each side is golden brown.
Using the spatula, remove to paper towels to drain.
If making the fried parsley garnish, add the parsley sprigs to the hot oil and fry just until lightly crisped—about 30 seconds.
Transfer to the paper towels to drain.
Sprinkle the cooling blossoms with coarse sea salt and top with the parsley, if using. Serve immediately.